- In a glass mixing bowl, combine the wasabi powder and the water. Mix until a paste forms.
- Add the softened butter, scallions, garlic, mustard, sugar, egg yolks, ginger, ½ cup of sesame seeds, and the bread crumbs. Mix together well.
- Rinse the tuna steaks and pat with paper towels until the steaks are very dry.
- Divide the wasabi-crumb mixture in four pieces, and then each piece in half. Pat the mixture onto each steak, covering each side well.
- In a small bowl, combine the tamari, orange juice, and remaining two tablespoons of sesame seed.
- In a skillet over medium-high heat, heat the olive oil. When the oil is hot, add the tuna to the skillet. Turn the steaks over after 1 ½ minutes, so that a crust should begin to form and turn brown on each side. For us, I let the steaks cook no more that about 2 - 3 minutes on each side. If you want them more done, lower the heat and cook 5 minutes on each side.
- Serve the tuna hot with a drizzle of the tamari sauce.