1 tablespoon olive oil
1 1/2 cups thinly sliced onion
4 garlic cloves, minced
3 pounds ripe tomatoes, chopped
1 cup sliced pitted olives, divided
1/2 cup water
1/4 cup capers, divided
1/4 cup sliced pickled jalapeño peppers, divided
3 tablespoons chopped fresh flat-leaf parsley
1 1/2 teaspoons dried Mexican oregano
3 bay leaves
1 teaspoon salt, divided
6 (6-ounce) red snapper or other firm white fish fillets
1/4 cup fresh lime juice
Flat-leaf parsley sprigs (optional)
Heat the olive oil in a Dutch oven over medium-high heat. Add onion and garlic, and sauté for 5 minutes or until lightly browned. Add tomatoes, 1/2 cup olives, water, 2 tablespoons capers, 2 tablespoons jalapeños, parsley, oregano, and bay leaves. Bring to a boil; reduce heat, and simmer 30 minutes or until reduced to 6 cups. Stir in 1/2 teaspoon salt. Discard bay leaves.
Arrange fish in a single layer in a 13 x 9-inch baking dish; drizzle with lime juice, and sprinkle with 1/2 teaspoon salt. Cover and marinate in refrigerator 30 minutes; discard marinade.
Preheat grill to 350°.
Spoon sauce over fish. Bake at 350° for 15 minutes or until fish flakes easily when tested with a fork. Sprinkle with 1/2 cup olives, 2 tablespoons capers, and 2 tablespoons jalapeños. Garnish with parsley sprigs, if desired.