Gather the ingredients. If the hamachi kama is frozen, thaw it beforehand by placing the fish, still in its vacuum-sealed package, in a bowl under a thin stream of cold running water for 20 minutes. Alternatively, you can put the fish in a bowl of iced water to defrost for 2 hours (takes longer but saves water), or in the refrigerator for 9 hours.

Preheat the broiler with a rack placed about 6 inches (15 cm) away from the top heating element (in the center of the oven) for 5 minutes.

Crinkle a sheet of aluminum foil and line the baking sheet. This helps prevent the fish skin from sticking to the foil.

Place 2 pieces hamachi kama (yellowtail collar) on the foil, skin side down. Sprinkle ⅛ tsp Diamond Crystal kosher salt over the fish.

Broil on Medium (500ºF/260°C) for 8–10 minutes until the surface is blistered and browned a bit.

Preheat the oven to 425°F/218ºC with a rack placed in the middle and bake for 10–12 minutes, until the edges are crispy and the top is golden brown and opaque.

To make the yuzu-flavored soy sauce, mix 1 Tbsp soy sauce and ½ tsp yuzu juice (extract) together and divide into individual small dipping dishes.

Serve the freshly grilled fish immediately on individual plates with the dipping sauce on the side and an optional 2 wedges lemon. Squeeze the lemon over the fish and dip the Hamachi Kama lightly in the sauce to eat.