The leftover braising oil is extremely flavorful. You can toss it with pasta or use it in dressings.

　　This recipe is an accompaniment for Monkfish and Clam Bourride .

　　

Ingredients

Makes about 3 cups

　　1 medium white onion, chopped

　　3 garlic cloves, smashed

　　3/4 cup plus 2 tablespoons extra-virgin olive oil

　　9 fresh basil leaves

　　1/8 teaspoon dried hot red pepper flakes

　　12 plum tomatoes (2 pounds), halved lengthwise

　　1 teaspoon sugar

　　1/2 teaspoon kosher salt

　　

Step 1

Preheat oven to 250°F.

　　

Step 2

Cook onion and garlic in 2 tablespoons oil in a 12-inch heavy skillet over moderate heat, stirring occasionally, until softened, 5 to 7 minutes. Remove from heat and stir in basil and red pepper flakes.

　　

Step 3

Toss tomatoes with sugar and salt in a bowl. Arrange tomatoes, cut sides down, in a roasting or baking pan (13- by 9-inch). Spoon onion mixture over tomatoes and add enough of remaining 3/4 cup olive oil to reach halfway up tomatoes. Braise in middle of oven, stirring gently halfway through cooking, until tomatoes are very tender but not falling apart, 2 1/2 to 3 hours.