There is a charm to unaju you can only get from unaju, not from unadon in a bowl or hitsumabushi. It is the same eel and rice, only the box changes, and with it, how the whole thing looks in front of you.
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Unaju
Recipe Snapshot
- What is it? A premium Japanese eel dish, kabayaki glazed in a sweet-savory eel sauce and arranged over rice in a lacquered jubako box. Only the vessel and the amount of eel separate it from unadon, the same dish in a bowl.
- Flavor profile: Sweet and savory in equal measure, the caramelized soy-mirin glaze playing against rich, fatty grilled eel, with a bright tingle of sansho cutting through at the finish.
- Why you will love this recipe: It lands the restaurant luxury at home for less than half the price, and that moment you open the lid is pure contrast: the dark box, the white canvas of rice, the glossy brown eel laid across it.
- Must-haves: An eel fillet, the soy-sake-mirin trio for the tare, and a grill or broiler to crisp and glaze.
- Skill level: Medium.
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What Is Unaju?
Unaju (うな重) is grilled eel coated in a sweet, savory unagi sauce, laid over rice and served inside a stacked lacquer box called a jubako. The same eel in a donburi bowl is unadon, and chopped over rice it becomes hitsumabushi. Only the box changes, and it changes how the whole thing meets your eye.
For this recipe, I am not asking you to fillet a live eel or chase anything exotic. The honest truth about getting raw eel outside Japan comes later. What I want you to walk in believing is that technique matters.
Unajyu Ingredients
- Eel (unagi): This is the ingredient I will not pretend you can swap, and it takes a little hunting. In Japan, unless you are buying straight off the market, the eel you find is already filleted and opened flat. In North America, your realistic paths are raw butterflied fillets from a farm like American Unagi, or a good frozen fillet.
- Soy sauce, sake, and mirin: These 3 are the heart of the sauce, and I mean that literally. Use a Japanese koikuchi soy sauce, real sake, and hon mirin, because each is doing a different, equally important job.
- Sugar (turbinado plus a little dark brown): Here is a personal opinion rather than a rule. I build the sauce on coarse turbinado sugar (zarame) with a little dark brown sugar folded in, because I want a rich, deep sweetness with some body behind it.
Substitution Ideas
- Eel → Anago (conger eel): Anago is the closest stand-in by look. It is leaner and milder, a lighter cousin rather than a true match, but glazed with this same kabayaki sauce over rice it makes a genuinely good bowl.
- Eel → Catfish: This one will probably surprise you, but catfish goes perfectly with unagi sauce. It is a different fish and a different bowl, not a copy, yet it is good in its own right. Think of it as its own thing rather than a fake unagi.
- Soy sauce → Tamari: This is the one swap inside the sauce trio I am happy to give you. Tamari steps in cleanly for the soy, and it is your move for a gluten-free version. Beyond that, I would keep the soy, sake, and mirin as they are.
Have trouble finding Japanese ingredients? Check out my ultimate guide to Japanese ingredient substitutes!
How to Make My Unaju
If you prefer to watch the process in action, check out my YouTube video of this unaju recipe!
i. Add your turbinado sugar and dark brown sugar to a small saucepan and set it over medium-low heat. Let the sugar start to melt.
ii. Once it begins to melt, pour in the sake and mirin and bring it to a boil. Let it bubble for a couple of minutes, stirring now and then so nothing catches.
iii. Drop the heat to a simmer and add the soy sauce. If you have the eel bones and head, grill them and drop them in now for an extra layer of eel flavor, then strain them out at the end.
iv. Simmer it down until it turns thick and syrupy, stirring occasionally so the sugar does not scorch. Pull it off the heat and let it cool while you deal with the eel.
i. Rinse the eel fillets under cold running water and pat them completely dry with kitchen paper.
ii. Lay a sheet of plastic wrap over your cutting board and put the eel on top. Eel is slippery, and the wrap gives you grip and a clean cut.
iii. Cut each fillet into halves or thirds. The trick is to hold the knife still and move the eel back and forth underneath it rather than sawing down through it, so the flesh does not tear.
i. Lay the eel skin side down in your frying pan and pour in the sake.
ii. Put the lid on and steam it over medium-low heat. While it steams, get your grill or broiler heating to medium-high.
This is the step that changed how my eel turns out at home. For a long time I grilled it straight, and the result was hit or miss, sometimes rubbery skin, sometimes a dried-out inside. A short steam with sake softens the flesh and renders some fat, and the eel comes out melt-in-your-mouth inside with skin that still crisps.
iii. Pull the pan off the heat and move the eel onto your foil-lined wire rack, skin side down, ready for the grill.
i. Grill the eel flesh-side first (in my case, the heat source is up). Eel shrinks fast, and starting with the flesh side keeps the fillet from curling up and breaking apart on you.
ii. Turn it over and grill the skin side until it is lightly charred. Keep an eye and a nose on it. A little char is the smoky reward you are after.
On a home grill, completely blackened skin does not taste like charcoal smoke, it tastes burnt and bitter. Real charcoal is the one thing I cannot hand you at home, so chase color and aroma, not a hard timer. Pull it when the skin is glossy and lightly charred, before it goes black.
i. Brush the sauce generously over the skin side and return it to the grill for a moment, just long enough to set the glaze. Usually 20-30 seconds depending on the efficiency of your grill/broiler.
ii. Flip it, brush the flesh side, and grill again briefly. Repeat this brush-and-grill a few times on each side.
A single thick coat slides off and burns. Several thin ones bond, deepen the color, and drive the sweet-savory flavor into the surface of the eel. This layering is the difference between sauce that drips away and a glaze that becomes part of the eel.
iii. Each coat builds another thin layer of that lacquered shine and lets the sauce soak into the eel instead of just sitting on top.
i. Spread your warm rice into the jubako (or a donburi bowl, the food is the same) and brush a little of the leftover unagi sauce across the surface of the rice.
ii. Lay the eel on top, drizzle on any remaining sauce, and finish with a pinch of sansho pepper.
iii. Now lift the lid and appreciate its’ beauty before you eat. The dark box, the white rice, the glossy brown eel. That sight is the whole point, and you made it at home.
Essential Tips & Tricks
- Steam before you grill, every time. A few minutes of sake steam is the move that separates melt-in-your-mouth eel from a rubbery, dried-out fillet. The steam softens the flesh and renders a little fat so the inside stays tender while the skin still crisps on the grill.
- Lay the eel directly under the heat source. I keep the fillets lined up right beneath the burner of my gas fish grill so the whole surface chars evenly. Eel cooks fast and unevenly if part of it sits off to the cooler edge, and you end up with a glossy patch at the center and pale, undercooked tips.
- Set a timer and still glance at it. I once looked away and let mine catch a little too much char, so now the timer is not optional for me, and I check it by eye on top of that. Completely blackened skin on a home grill does not read as smoky, it reads as burnt and bitter. The timer keeps you honest, and the quick look catches the moment the glaze tips from glossy to scorched.
- Build the glaze in thin coats rather than a single heavy layer. A thick coat of sauce slides off and burns before it sets, while several thin brush-and-grill passes bond to the surface and deepen the color with each round. This is what gives you that lacquered shine instead of sauce pooling at the bottom of the box. Patience here is the whole difference between a glaze and a puddle.
Nail the sake steam and the thin-layer glaze, and home eel stops being a gamble.
Storage & Meal Prep
Fridge: Honestly, I do not store unaju, and I would steer you away from it too. The recipe is portioned so there is nothing left but maybe a little extra tare for drizzling, and a finished box is meant to be eaten the day you build it. If you absolutely have to hold cooked eel, keep it covered in the fridge for a day at the very most, but you are losing the whole reason you cooked it.
Freezer: Not recommended.
Meal prep: The one thing worth making ahead is the eel sauce. Build a batch of the soy-sake-mirin glaze, let it cool, and keep it in a sealed jar in the fridge so it is ready when you grill. The eel itself I would always cook the day you eat it. Prep the sauce, not the dish.
What to Serve With This Recipe
Unaju Troubleshooting
You almost certainly grilled it straight without steaming first. Raw eel grilled cold renders its fat unevenly, so the skin toughens before the inside turns tender. Give it a few minutes of sake steam in a covered pan before it ever touches the grill, and the flesh comes out soft while the skin still crisps under the heat.
The tare was under-reduced, so it ran off the eel instead of clinging in lacquered layers. Simmer it a little longer until it thickens to a slow, syrupy pour, then build the shine with several thin brush-and-grill passes rather than one wet coat. Each pass sets a layer and deepens the gloss, and that is what turns runny sauce into a proper glaze.
The fillet was pressed straight onto a bare rack and grabbed on as the proteins set. Line your rack with foil and start the eel skin side down, which both protects the flesh and keeps the fillet from curling and ripping. Move it with a wide spatula rather than tongs so you support the whole piece instead of tearing one end.
More Japanese Donburi Recipes
- Tekka Don (Tuna Rice Bowl)
- Marinated Maguro Zuke Don
- Fresh Kaisendon (Seafood Bowl)
- Negitoro Don with Green Onion
Hungry for more? Browse my full Japanese donburi recipe collection to find your next bowl.
Did You Try This Recipe?
I would love to hear your thoughts!
💬 Leave a review and ⭐️ rating in the comments below. 📷 I also love to see your photos – submit them here!
Unaju (Japanese Grilled Eel on Rice)
Ingredients
Unagi Sauce
- 3 tbsp turbinado sugar light brown with coarse texture
- 1 tsp dark brown sugar folded in with the turbinado for extra depth
- 5 tbsp sake
- 5 tbsp mirin
- 5 tbsp Japanese soy sauce (koikuchi shoyu)
Unagi don
- 300 g filleted freshwater eels
- 2 tbsp sake
- 2 portions cooked Japanese short-grain rice
- Japanese sansho pepper optional
My recommended brands of ingredients and seasonings can be found in my Japanese pantry guide.
Can’t find certain Japanese ingredients? See my substitution guide here.
Instructions
Unagi Sauce
- Take a small sauce pan and add 3 tbsp turbinado sugar and 1 tsp dark brown sugar. Place it on the stove over a medium-low heat.
- When the sugar begins to melt, add 5 tbsp sake and 5 tbsp mirin. Boil for 1 to 2 minutes, stirring occasionally to evenly distribute the heat.
- Lower the heat to a simmer and add 5 tbsp Japanese soy sauce (koikuchi shoyu). If you want to add extra depth to your sauce, add grilled bones and heads from the eels.
- Simmer for about 10 minutes or until thickened to a syrup-like consistency. Stir occasionally to prevent the sugar from burning. Remove from the heat and allow to cool while preparing the eel. (If you added the bones and heads, pour through a strainer and discard.)
Unaju
- Wash 300 g filleted freshwater eels under cold running water and pat them dry with kitchen paper. Lay a sheet of plastic wrap over a chopping board and place the eel on top. Cut into halves or thirds by gently pressing a sharp knife into the area you want to cut, and then move the eel back and forth rather than sawing with the knife.
- Take a large frying pan and place the eel skin side down in a single layer. Add 2 tbsp sake and place it on the stove.
- Place a lid on and steam for 3 minutes over a medium-low heat. While you wait, preheat the grill or broiler on medium-high.
- Lay a piece of foil over a wire rack, and place it over a baking tray. Arrange the steamed eel on the wire rack so that the flesh side will be facing the heat source, and grill for 6 minutes.
- Flip the eel over and grill the skin side for 5 minutes or until lightly charred.
- Brush the prepared sauce generously over the skin and return it to the grill for 30 seconds.
- Flip and apply the sauce to the meat side, then grill for 30 seconds. Repeat the brushing and grilling 3 times on each side, 6 times in total.
- Divide 2 portions cooked Japanese short-grain rice into a jubako (or similar box) for each portion, and brush the top with leftover unagi sauce.
- Arrange the unagi on top of the rice, drizzle with any leftover sauce and sprinkle with Japanese sansho pepper. Enjoy!
Very informative piece of recipe, I was very hesitant to even buy eel, but now I definitely have to do that;)
Hi Norbert,
Really glad this helped you take the leap! Eel is one of those ingredients that’s so worth trying once you get past the hesitation. Enjoy making it 😊
Yuto