Tuna ceviche and tuna burgers are two recipes made with fresh tuna fish. The tuna ceviche recipe is made with marinated tuna, whereas the tuna burger requires cooking the fresh tuna.
To make tuna ceviche, slice 1 pound of sushi-grade tuna into 1/4-inch thick pieces and freeze for 15 minutes. Stack the tuna slices and cut into 1/4-inch cubes. Transfer the tuna into a bowl and stir in 1 thinly sliced red onion, 3/4 cup of lime juice and 1 teaspoon of black pepper. Cover with plastic wrap and refrigerate for one hour, stirring every 15 to 20 minutes. Just before serving, fold in 1 diced avocado, 1/4 cup of chopped cilantro and salt to taste.
To make tuna burgers, cut 2 pounds of fresh tuna into 1/4-inch chunks and transfer to a bowl over ice. Add 1 minced garlic clove, 2 tablespoons of olive oil, 1 tablespoon of sesame oil, 1 minced anchovy fillet, 2 tablespoons of chopped basil, 2 minced celery stalks, 1 1/2 teaspoons of grated ginger, 1 teaspoon of salt and 1/4 teaspoon of black pepper. Mix well and form into 6 patties.
Grill on medium high heat for three to four minutes per side for rare burgers or seven to eight minutes per side for well-done burgers. Serve with pickled ginger, wasabi mayonnaise and mizuna on buns brushed with sesame oil.