•1 pound fresh sushi-grade skinless yellowfin tuna
•1 tablespoon kosher salt or sea salt, plus more to taste
•1 / 2 teaspoon fresh-ground black pepper
•Juice of 3 limes
•3 medium tomatoes, diced
•1 / 2 red onion, sliced into half moons
•1 small cucumber, peeled, seeded and sliced
•1 / 2 teaspoon minced ginger root
•1 small garlic clove, chopped
•2 scallions, chopped
•1 cup fine-chopped parsley
•2 tablespoons olive oil
•Mayonnaise, for serving
Have ready a large bowl of ice water. Cut the tuna into 1 / 2-inch pieces. As you finish cutting the pieces, place them in the ice water. When all are cut, swish them around in the water and drain.
Place tuna in a bowl and add salt, pepper, lime juice, tomatoes, onions, cucumbers, ginger root, garlic, scallions and parsley. Use your hand to combine thoroughly.
Cover and refrigerate about 20 to 30 minutes. (The acid will "cook" the tuna some, but leave it rare in the center; let it sit longer if you like the fish "cooked" more.)
To stop the "cooking," add the olive oil and mix well. Serve with mayonnaise on the side for stirring in at the table, if desired. Serve immediately. Will keep well refrigerated for two days. Makes about 4 cups.
Per (1-cup) serving without mayonnaise: 208 calories, 35 percent calories from fat, 8 grams total fat, 1 gram saturated fat, 51 milligrams cholesterol, 5 grams carbohydrates, 1 gram total fiber, 2 grams total sugars, 4 grams net carbs, 27 grams protein, 489 milligrams sodium.