1. In medium saucepan, combine 1/2 cup olive oil with parsley, red peppers, scallions, 2 tbsp. lemon juice, capers, oregano, and salt. Simmer over low heat 5 minutes, stirring occasionally, to blend flavors. Remove from heat and set aside.
2. Place tuna in a single layer in a glass baking dish. Drizzle remaining 1/4 cup olive oil and 2 tbsp. lemon juice over fish. Season with pepper. Turn to coat both sides. Cover with plastic wrap and marinate at room temperature 30 minutes.
3. Prepare a hot fire. Place fish on an oiled grill set 4 to 6 inches from coals. Reheat sauce by placing saucepan on side of grill. Grill tuna, turning once, until opaque throughout but still moist, about 8 to 10 minutes. Transfer to a serving plate and spoon sauce over each steak.
3/4 cup extra virgin olive oil
1/2 cup minced parsley
1/2 cup jarred marinated roasted peppers -- drained and diced
1/2 cup thinly sliced scallions
1/4 cup fresh lemon juice
2 tablespoons capers -- drained
2 tablespoons minced fresh oregano -- or
2 teaspoons dried oregano
1/4 teaspoon salt
6 8-oz tuna steaks -- about 3/4 inch thick
1/8 teaspoon freshly ground pepper