Combine tomatoes, peppers, onion, and water in a large Dutch oven; cook over medium heat about 30 minutes or until vegetables are tender.
Place vegetables and liquid in container of electric blender; set on high speed, and process until smooth.
Combine flour, oil, and garlic in a medium saucepan; cook over low heat, stirring constantly, until mixture is lightly browned. Add vegetable mixture; cook over low heat 15 minutes, stirring occasionally.
Oxmoor House Homestyle Recipes