Making The Sauce:

1. In a large fry pan over medium heat, warm the olive oil. Add the onion and sauté, stirring until soft, about 10 minutes.

2. Add the tomatoes, oregano, red pepper flakes, vinegar, tomato paste, red wine, sugar, salt and pepper. Bring to a simmer and cook gently, uncovered, until the sauce thickens, about 20 minutes. Stir 2 or 3 times during cooking to prevent scorching. Remove from the heat and let cool.

3. Transfer the sauce to a blender or to a food processor fitted with the metal blade. Puree until smooth. Taste and adjust the seasonings with salt and pepper. Use the sauce hot or at room temperature. The sauce may be stored in a tightly covered container in the refrigerator for up to 3 days or in the freezer for up to 2 months. 

This sauce is delicious tossed with pasta.