If using sesame seeds, spread white and black sesame seeds on a plate and press both sides of the tuna gently into the seeds so they adhere in a thin crust. Press firmly but avoid crushing the fish.

Make Soy-Ginger Dressing

In a small bowl, whisk together soy sauce, rice vinegar, sesame oil, grated ginger, honey, minced garlic, sliced scallion, and red pepper flakes until combined. Taste and adjust: add more honey for sweetness, more vinegar for tang, or a pinch more red pepper flakes for heat.

Cook Tuna

Heat pan

Heat a heavy skillet or cast-iron pan over medium-high heat until very hot (about 2–3 minutes). Add the remaining 1 tbs olive oil and swirl to coat.

Sear

Place tuna steaks in the hot pan. Sear without moving for 45–60 seconds for rare (bright pink/red center), 1.5–2 minutes per side for medium-rare (slightly pink center), or 3 minutes per side for medium. If sesame-crusted, handle gently when flipping so crust stays intact.

Rest and finish

Remove steaks to a cutting board and let rest 2 minutes. Squeeze lemon over the tops just before slicing to add brightness.

Assemble and Serve

Divide cooked rice and mixed greens between two plates (1 cup rice and 1 cup greens per serving). Thinly slice each tuna steak across the grain into 6–8 slices and arrange on top of rice and greens.

Drizzle soy-ginger dressing over the tuna and greens (about 1.5 tbs dressing per plate). Serve with lime or extra lemon wedges on the side. Leftover dressing can be refrigerated up to 3 days.