Rinse the sushi rice under cold water in a fine-mesh strainer, swishing with your hand, until the water runs mostly clear to remove excess starch. Add the rinsed rice and 2 1/4 cups water to a pot or rice cooker. If using a pot, bring to a gentle simmer, cover, and cook on low for 15–18 minutes, until the water is absorbed. Turn off the heat and let it sit, covered, for another 10 minutes to finish steaming.

While the rice cooks, stir together 3 tablespoons rice vinegar, 1 1/2 tablespoons sugar, and 1 teaspoon fine sea salt in a small bowl until the sugar dissolves. Transfer the hot cooked rice to a wide bowl. Drizzle the vinegar mixture over the rice and gently fold using a cutting and turning motion to avoid smashing the grains. Let the seasoned rice cool to warm or room temperature so it doesn’t wilt the toppings.

Cut the sushi-grade salmon and tuna into small bite-sized cubes. If using tofu, press it between paper towels or a clean kitchen towel for 15–20 minutes to remove excess moisture, then cube it. If desired, lightly sear the tofu in a little oil for browned edges, or leave it plain for a lighter bowl. If using cooked shrimp or crab, ensure it is fully cooked, cooled, and cut into bite-sized pieces if large.

In a medium bowl, whisk together soy sauce (or tamari), 1 tablespoon rice vinegar, toasted sesame oil, sriracha or other hot sauce, mayonnaise, and honey or sugar. Taste and adjust: add more sriracha for a spicier sauce or a pinch more sweetener if you prefer it slightly sweeter. Set aside 1–2 tablespoons of this mixture for drizzling over the finished bowls.

Add the cubed salmon, tuna, or tofu to the bowl with the sauce and gently stir to coat all sides. Marinate in the refrigerator for 10–15 minutes while you prepare the vegetables and toppings. If using cooked shrimp or crab, toss it lightly with some of the sauce just before serving to avoid a rubbery texture.

Slice or cube the avocado. Thinly slice or julienne the cucumber and carrots. If needed, cook the edamame in boiling water for 3–4 minutes, then drain and rinse with cold water. Thinly slice the green onions. Cut or tear the nori sheets into thin strips or crumble seaweed snack sheets into small pieces.

Fluff the seasoned sushi rice and divide it evenly among 4 bowls as the base. Top each bowl with a portion of marinated fish or tofu, arranging it slightly off-center. Add generous piles of cucumber, avocado, carrots, and edamame around the bowl. Sprinkle with sliced green onions, toasted sesame seeds, and nori strips. Drizzle a little of the reserved sauce and/or extra soy sauce on top. Add pickled ginger, a small dab of wasabi, and lime or lemon wedges on the side if desired.

Taste and adjust each bowl at the table: add more cucumber or carrots for crunch, extra soy sauce or tamari for saltiness, or a drizzle of sesame oil or sauce for richness. Sprinkle with furikake if using. Serve right away while the rice is slightly warm and the toppings are cool and fresh.