Puttanesca Sauce | America's Test Kitchen

Ingredients

• 2 tablespoons unsalted butter
• 1/4 cup finely chopped onion
• 4 anchovy fillets, rinsed and minced
• 1/2 teaspoon red pepper flakes
• 1/2 teaspoon table salt
• 1/4 teaspoon dried oregano
• 2 garlic cloves, minced
• 1 (28-ounce) can crushed tomatoes
• 1/4 teaspoon sugar
• 1/4 cup pitted kalamata olives, chopped
• 3 tablespoons capers, rinsed and minced
• 1 tablespoon extra-virgin olive oil