How to Make It
Heat a large skillet over medium-high heat. Add oil; swirl to coat. Add onion and next 5 ingredients (through red pepper); sauté 8 minutes. Add tomato paste; cook 2 minutes, stirring frequently. Add wine; cook 2 minutes or until liquid almost evaporates.
Combine vegetable mixture and tomatoes in an electric slow cooker. Cover and cook on LOW for 8 hours. Place 3 cups tomato mixture in a blender. Remove center piece of blender lid; secure lid on blender. Place a clean towel over opening in blender lid. Blend until smooth. Return tomato mixture to slow cooker. Add basil, salt, and black pepper. Cook, uncovered, on HIGH 30 minutes.