- 2 tablespoons olive oil
- 1/4 cup chopped onions
- 1 tablespoon minced garlic
- 3 Italian plum tomatoes, finely chopped
- 1/3 cup pitted and halved black olives, such as ProvenÁal, Greek or Italian
- 1/3 cup halved pimiento-stuffed green olives
- 2 teaspoons finely minced anchovy fillets or anchovy paste
- 1 tablespoon chopped parsley
- 1 tablespoon chopped basil
- 1 teaspoon chopped oregano
- 1 teaspoon salt
- Black pepper
- 1 stick unsalted butter, cut in 8 pieces (8 tablespoons) chilled
- Heat oil in a large skillet over high heat. Add onions and sauté 1 minute. Stir in garlic, tomatoes, black and green olives, anchovies, parsley, basil and oregano; season with salt and 10 turns of pepper. Bring to a boil and simmer, stirring occasionally, about 3 minutes.
- Reduce heat to medium and add butter pieces, stirring. When butter is half melted, remove skillet from heat and continue stirring until thoroughly incorporated.