3/4 cup finely chopped onion
2 tablespoons olive oil
2 garlic cloves, minced
1 1/2 pounds plum tomatoes, peeled, seeded, chopped (or a 28-ounce can)
4 flat anchovy fillets, drained, minced
1/2 cup dry white wine
1/4 teaspoon dried red pepper flakes
1 teaspoon dried thyme
1 1/2 pounds sea bass or halibut fillets (1/2 to 3/4 inch thick)
2/3 cup Niçoise black olives, pitted, sliced
1 tablespoon capers, drained
1 tablespoon shredded fresh basil leaves

In a large skillet cook onion in oil over moderately low heat, stirring, until softened. Add garlic and cook mixture, stirring, 30 seconds. Add tomatoes and anchovies and cook mixture over moderately high heat, stirring, 5 minutes. Add wine, red pepper flakes and thyme and bring mixture to boil, stirring. Reduce heat to low, add bass and season it with salt and pepper. Cook bass, covered, 3 to 4 minutes on each side, until just cooked through. Transfer bass to a heated platter and keep it warm, covered. Boil sauce, stirring, until thickened, add olives, capers and salt and pepper to taste. Simmer 2 minutes. Discard any liquid from platter, spoon sauce over bass
and sprinkle with basil. Serve hot or at room temperature. Serves 4.