Whisk together 2 Tbsps olive oil, 1 Tbsp soy sauce, 1 tsp wasabi paste, 1 tsp rice wine vinegar, and 1 tsp shredded ginger. Dip the tuna piece into the olive oil mix, turning to coat on all sides, then coat with the sesame seeds. Set a dry pan on the stove to medium-high heat. Turn, searing on all sides. Remove tuna and slice.
Salad Assembly
Toss the lettuce with the dressing. Place the carrots over the lettuce. Place the tuna pieces over the salad. Mix the 1 tsp wasabi paste, 1 Tbsp soy sauce, and 1 tsp ginger. Drizzle the soy mixture over the tuna. Serve.