Baked Halibut With Tomato Caper Sauce

This is a pungent tomato sauce that I learned to make in Provence. It goes well with any type of robust fish.

1 tablespoon extra virgin olive oil
½ medium onion, finely chopped
4 plump garlic cloves, minced or mashed in a mortar and pestle
¼ cup capers, drained, rinsed and finely chopped or mashed with the garlic in a mortar and pestle
2 pounds tomatoes, peeled, seeded and finely chopped, or 1 28-ounce can diced tomatoes with juice
Salt, preferably kosher salt
freshly ground pepper to taste
Pinch of sugar
1 teaspoon chopped fresh thyme leaves
1 tablespoon slivered fresh basil leaves

1 recipe tomato-caper sauce, above
6 6-ounce halibut fillets (Choose Pacific halibut over Atlantic halibut. According to the Environmental Defense Fund and the Blue Ocean Institute, Pacific halibut fisheries have been properly managed, but they are overfished in the Atlantic.)
Salt, preferably kosher salt
freshly ground pepper
1 tablespoon extra-virgin olive oil
6 lemon slices

Nutritional Information
- Nutritional analysis per serving (6 servings)
  254 calories; 7 grams fat; 1 gram saturated fat; 4 grams monounsaturated fat; 1 gram polyunsaturated fat; 13 grams carbohydrates; 4 grams dietary fiber; 8 grams sugars; 34 grams protein; 83 milligrams cholesterol; 659 milligrams sodium

Serves 6

Heat the olive oil in a large, heavy skillet over medium heat, and add the onion. Cook, stirring often, until tender, three to five minutes, and add the garlic and the capers. Cook, stirring, for three to five minutes, until the onion has softened thoroughly and the mixture is fragrant. Add the tomatoes, salt, pepper and a pinch of sugar. Stir in the thyme, bring to a simmer and cook, stirring often, for 15 to 20 minutes, until the sauce is thick and fragrant. Taste and adjust seasonings. Serve hot or cold.
Make the sauce as directed and keep warm.
Preheat the oven to 450 degrees. Oil a baking dish large enough for the fish to lie flat. Season the fish with salt and pepper, and arrange in the baking dish. Drizzle the olive oil over the fillets, and place a round of lemon on each one. Cover the dish tightly with foil, and place in the oven. Bake 15 minutes. Check the fish; if you can cut into it with a fork, it is done. If it doesn’t yield, (halibut fillets tend to be thick can take time to cook), cover and return to the oven for five minutes. Remove from the oven, and check again. Remove the lemon slices from the fish.
Place a spoonful of sauce on each plate, and place a piece of fish partially on top. Spoon some of the liquid from the baking dish over the fish. If you wish, top the fish with another spoonful of sauce, garnish with basil leaves and serve.

Advance preparation: The sauce will keep for about five days in the refrigerator.

1 hour