2 tablespoons olive oil
2 – 4 tablespoons finely chopped sweet or yellow onion
2 cloves garlic, minced
1/2 teaspoon dried oregano
1/4 teaspoon dried red pepper flakes
28 ounce can whole or chopped tomatoes such as San Marzano
Warm the oil over medium heat in a skillet. Add the onion and cook for one minute, then add the garlic and cook for 1 minute more. Add the tomatoes, a pinch of salt and optional spices if desired. Cook, stirring frequently, until most of the juice is evaporated, leaving a thick sauce. Taste and adjust salt and pepper as needed. Cool slightly before use.