Asian Tuna Burgers with Wasabi Mayo
Prepare a medium-hot fire in a grill. Oil the grill grate or a perforated grill rack.
To make the wasabi mayo, combine all the ingredients in a food processor and process until smooth. Taste and adjust the seasonings. Transfer to a bowl, cover, and refrigerate. (Wasabi mayo can be made 1 day ahead of time.)
Combine the tuna, garlic, ginger, sesame oil, soy sauce, scallions, salt and pepper in a large bowl. Form the mixture into six 1-inch-thick patties.
Grill the burgers until browned on both sides and cooked to the desired degree of doneness (the middle can still be reddish pink), 5 to 7 minutes total.
To assemble and serve the burgers, place each burger on a toasted bun and top with the wasabi mayo and mizuna.
Wasabi Mayo
¼ cup plus 2 tablespoons mayonnaise
3 tablespoons finely chopped scallions (white parts with some of the green)
2 teaspoons grated fresh ginger
2 teaspoons soy sauce
1 teaspoon wasabi paste or powder
Burger
One 12-ounce tuna steak or fillet, cut into ¼-inch dice, skin and any bones discarded
2 cloves, garlice, minced
2 teaspoons grated fresh ginger
1 tablespoon toasted sesame oil
3 tablespoons soy sauce
¼ cup finely chopped scallions (white parts with some of the green)
½ teaspoon kosher or coarse sea salt
¼ teaspoon fresh ground black pepper
6 sesame seed buns, cut in half and toasted
1 cup fresh mizuna or other baby Asian greens