Step 1 In a 2-quart heavy-bottom saucepan, heat the oil over medium-high heat just until it begins to ripple, about 2 minutes. Stir in the onions and garlic and cook, stirring frequently until the onions are translucent. Stir in the basil, tomatoes, salt and pepper and continue to cook, stirring frequently, until the tomatoes break down and the sauce just coats the back of a spoon, about 20 minutes. Remove from heat. This makes about 2 cups sauce.