In a large saucepan heat the remaining 1 tablespoon oil over medium. Add onion and garlic; cook 5 to 7 minutes or until onion is tender, stirring occasionally. Add tomatoes, sweet pepper, vinegar, salt and 1/4 teaspoon of the black pepper. Bring to boiling; reduce heat. Simmer, uncovered, 20 to 30 minutes or until tomatoes have broken down and mixture is slightly thick, stirring occasionally. Cool slightly. Blend with an immersion blender until smooth. Return to saucepan; heat through. Stir in herbs. Transfer half of the sauce to a freezer container, let cool, and freeze up to 3 months.