In a food processor, combine 2 cans of stewed tomatoes, 1 can of tomato paste, 4 tablespoons of chopped parsley, 1 minced garlic clove, 1 teaspoon of oregano, 1 teaspoon of salt, and 1/4 teaspoon of ground black pepper.
Blend the mixture until smooth.
In a large skillet, heat 6 tablespoons of olive oil over medium heat.
Add 1/3 cup of diced onion and sauté for 2 minutes.
Pour the blended tomato mixture and 1/2 cup of white wine into the skillet with the onions.
Stir the sauce to combine the ingredients.
Allow the sauce to simmer for 30 minutes, stirring occasionally.