Heat 2 tablespoons olive oil in a large saucepan over medium heat
Add 1 chopped onion and cook until soft
Add 3 to 4 minced garlic cloves and cook for 30 seconds
Stir in 1 can crushed tomatoes
Add 1 can tomato sauce
Add 2 tablespoons tomato paste
Add 1 teaspoon salt
Add 1/2 teaspoon black pepper
Add 1 teaspoon dried oregano
Add 1 teaspoon dried basil
Add 1/2 teaspoon sugar
Add 1/4 teaspoon red pepper flakes if desired
Stir well and bring to a gentle simmer
Reduce heat to low and cook for 20 to 30 minutes, stirring occasionally
Taste and adjust seasoning as needed
Stir in fresh basil or parsley if desired
Serve over cooked spaghetti