Preheat grill. Brush steaks with oil and season with salt and pepper to taste. Grill for 1 minute on each side (just to obtain grill marks) Remove and slice each steak into 8 slices.
Place 1 cup of mizuna on each plate. Divide avocado and tomatoes among plates. Drizzle with the wasabi vinaigrette.
Whisk together all ingredients until combined. Season with salt and pepper to taste
Recipe courtesy of Bobby Flay