Fill a large bowl with cold water and add a splash of sake (optional). Submerge 2 yellowtail collars and gently rub the surface, removing any blood clots or dark residue.
Drain and rinse with cold water, then dry both sides of the yellowtail collars thoroughly with kitchen paper.
Score the skin side with a cross, about 1-2cm deep (avoid cutting through the bone).
Season with sea salt, about 2% of the yellowtail collar's weight. Sprinkle from a height for more even coverage, salt both sides and rub it gently if needed for even distribution.
Place in a sealable container and rest in the fridge for 30 minutes.
After 30 minutes, preheat your grill to medium heat (around 175-200°C/350-400°F). While it heats up, gently press kitchen paper on both sides of the yellowtail collars to blot away excess moisture without removing too much salt.
Place the collars on the grill with the flesh side facing the heat source. Once fully preheated, grill for 5 minutes.
Gently flip and grill the skin side for 9 minutes or until deeply bronzed and crispy. Check doneness by piercing the thickest part with a chopstick or paring knife, the flesh should flake away from the bone with no resistance.
Plate up with a mound of grated daikon radish (daikon oroshi) drizzled with a few drops of Japanese soy sauce (koikuchi shoyu). Serve with citrus of choice and enjoy!
Notes
Choose fresh collars by checking for moist (not slimy) appearance, firm flesh, and springy skin. Frozen packs from Asian groceries work well and are often affordable.Collar substitutions: Salmon collar is fattier and more forgiving, tuna collar offers steak-like intensity, sea bream is leaner but delicate (watch carefully), swordfish or amberjack work if they show visible marbling.Test doneness by inserting a chopstick near the thickest part and twisting gently. Meat should flake in moist layers and pull from bone with no resistance. If translucent or clinging, cook 1-2 more minutes.Storage: Refrigerate wrapped tightly up to 2 days (skin loses crispness); freeze wrapped in plastic, then foil, then bag for 2-3 weeks maximum before fat oxidizes.Reheat in toaster oven or fish grill 2-3 minutes on low-medium to restore crispness, or microwave uncovered 30-60 seconds at 600W with a sake sprinkle for moisture.Serving ideas:Kohaku Namasu, Spinach Ohitashi Salad, Goya Champuru, Hiyayakko (Cold Tofu)