Season the tuna. Pat the tuna dry, cut it into small cubes, then toss it in the sauce to coat.
Sear. Get a skillet very hot over high heat. Add the tuna and sear, tossing often, for about 45 seconds to 1 minute for a rare center, up to 2 minutes if you want it cooked through (Note 2).
Build the bowls. Divide the rice between four bowls. Arrange the avocado, edamame, carrots, cucumber, mango, kimchi, and pickled onion around the rice. Top with the tuna. Finish with sriracha and sesame seeds.
1 lb tuna steak, cut into small cubes (Note 1), 2 cups sushi rice, raw, cooked (yields about 4 cups / 800g cooked — Note 5), 2 avocados, 1 cup cooked edamame, 2 medium carrots, 1 English cucumber, 1 mango, 1 cup kimchi, ½ cup pickled red onion, Sriracha, 2 tsp sesame seeds
Notes
Note 1 — Tuna: Cut the steak into roughly ½-inch cubes — small enough to sear quickly, big enough that they don't overcook in seconds. You do not need sashimi-grade here — regular fresh tuna steak from the seafood counter works fine since it's being cooked.Note 2 — Doneness: 45 seconds to a minute gives you a warm, rare center, similar to tataki. Closer to 2 minutes cooks it through if you'd rather skip the pink middle entirely. Either way works in the bowl.Note 3 — Chicken swap: Prefer chicken over fish, or feeding someone who won't eat seafood? Use 1 lb chicken breast, cut into small cubes, in place of the tuna. Toss it in the same sauce, then cook in a skillet over medium heat until golden and cooked through, about 6-8 minutes. Everything else in the recipe stays the same.Note 4 — Canned tuna version: Skip searing altogether. Drain 2 cans of tuna and toss it straight in the sauce. It's a different texture to seared tuna, but it's on the table in under 10 minutes.Note 5 — Rice: Rinse the 2 cups raw rice until the water runs mostly clear, then cook with about 2¼ cups water (check your rice cooker or package instructions for exact ratio). This gives you roughly 4 cups cooked — 1 cup per bowl. Let it cool to warm, not hot, before building the bowls. Straight off the stove, it wilts the toppings and softens the avocado too fast.