Pan Fried Japanese Teriyaki Salmon

Wash 100 g Chinese spinach with cold water and cut it into 3 parts, the stems, the middle and the leaves. Tie each bundle together with butcher's string. (If you're only using the spinach leaves you can skip these steps.)
Bring a small pot of water to a boil and add a pinch of salt. Prepare a bowl of ice-cold water next to it.
Add the spinach stems to the water and set a timer for 1 minute.
After 1 minute, add the middle part and set a timer for 45 seconds, leaving the stems in.
After 45 seconds, add the leaves and boil all the spinach together for 30 seconds.
Transfer all the bundles to the bowl of ice cold water and leave to cool for 1-2 minutes. Gently squeeze the spinach to remove the water and place on a piece of kitchen paper to absorb the excess.
Heat a pan on medium and melt 1 tbsp unsalted butter. (Alternatively, you can start this step half way through cooking the salmon so that they're ready at the same time.)
Add the spinach and 100 g asparagus to the pan along with a pinch of salt and pepper. Stir fry for 2-3 minutes and then remove from the heat. Set aside for later.

In a small bowl, mix the 1 ½ tbsp soy sauce, 1 ½ tbsp mirin, 1 ½ tbsp sake and 1 tsp sugar until the sugar is dissolved to make the teriyaki sauce. Set aside for later.
Heat a frying pan on medium. While it heats, dry the surface of 2-4 small salmon fillets with kitchen paper and sprinkle each side with a pinch of salt and pepper.
Sprinkle the salmon with 1 tbsp potato starch, rubbing it over both sides to create a thin even layer. Gently tap and brush off any excess starch.
Once the pan is hot, add 1 tbsp cooking oil and place the salmon fillets in the pan with the skin side down. Fry for approximately 4 minutes or until the skin is crispy.
Flip the salmon fillets and fry on the other side for 2 minutes.
Pour the teriyaki sauce over the salmon. Move the salmon around the pan so that the sauce sticks to the bottom and spoon it over the top to coat the skin side.
Once the sauce is thick, glossy and the salmon is well covered, remove the pan from the heat.
Dish up 2 portions cooked Japanese short-grain rice and top with a bed of buttery spinach.
Place the salmon fillets on top and arrange the asparagus next to them. Pour the leftover sauce from the pan over the salmon and garnish with toasted sesame seeds and finely chopped green onions (optional).
Enjoy!