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.
Yield: 1 1/3 cups