Step 1

Whisk or blend together vinegar, soy sauce, ginger, garlic, wasabi (or horseradish), and sugar. Marinate fish in sauce for 15-30 minutes. (Refrigerate while marinating.)

Step 2

Preheat oven to 400°F.Brush oil in an oven-safe pan or casserole dish.Use your fingers to brush the marinade off of the fish and move it to the prepared pan. Reserve marinade.Slide the pan into the oven.Cook fish for 8 minutes per 1" thickness, or until the fish is opaque and easily pierced with a fork. (Thinner fish will be done cooking in less time, so pay attention to the thickness of your fillets.)Do not flip the fish halfway through cooking.

Step 3

While the fish cooks, pour the marinade into a small pot.Heat over medium heat until it comes to a boil, and then simmer for 2-3 minutes, lowering heat if necessary. Remove from heat and cover the pan to keep the sauce warm.

Step 4

When the yellowtail is done cooking, remove it from the oven and brush the teriyaki sauce over the fish. Divide the remaining sauce and serve it on the side or drizzled over side dishes (like rice or vegetables.)Serve the fish immediately.