In a medium-size saucepan over medium heat add the olive oil and when hot add the onion. Cook the onions for 5 to 6 minutes or until translucent. Add the garlic and continue to cook, stirring for 3 minutes longer. Add the tomatoes and basil and using the back of a wooden spoon, gently crush the tomatoes.  Cook the tomatoes, stirring occasionally for 30 minutes. Season with salt and pepper.

Remove from the heat and cool slightly. Using a hand mixer or blender puree the sauce until almost smooth.

Sauce can be frozen or stored in the refrigerator for up to 1 week.