Basic Red Sauce

Heat oil in a medium saucepan over medium heat. Cook onion and garlic, stirring occasionally, until tender, about 5 minutes. Stir in tomato paste.

Add pureed tomatoes, basil, oregano, red-pepper flakes, and 1/2 teaspoon salt. Season with pepper, and bring to a simmer. Reduce heat, and gently simmer, stirring occasionally, until sauce is thick, 25 to 30 minutes.