In a mixing bowl or ziplock bag mix together soy sauce, sesame oil, honey, 1/4 tsp salt and pepper. Add tuna steaks, coating well, and let sit for 10 minutes (you can do this step the night before and allow marinate overnight).

Peel shallots and remove both ends. If you are using larger shallots, slice them horizontally to about 1 inch slices. Rough slice mushrooms. Lightly salt and pepper both shallots and mushrooms. Add 1 tablespoon olive oil to non-stick skillet on medium high heat. When pan is hot add shallots, cut side down. Cook 3-4 minutes until surface is lightly browned and starting to caramelize. Turn each slice to brown on the other side. Move shallots to one side of the skillet, and add mushrooms to open side. Lower heat to medium and cook mushrooms for 2 minutes, stirring occasionally. Sprinkle with balsamic and stir. Remove both shallots and mushrooms to a plate.

Add remaining olive oil to the pan and heat to high. Remove steaks from marinade and pat dry. Press toasted sesame seeds (if using) onto both sides of each steak. Place steaks into hot pan and sear for 2 minutes on each side for medium rare, or 3 minutes on each side for medium. Remove to cutting board and allow to rest for 3 minutes.

Slice into 1/2 inch slices and serve with mushrooms and shallots. Delicious served over rice or in a noodle bowl as well.