Heat oil in a large saucepan, add garlic, onion, sugar, green pepper, and carrot. Cook over a medium heat, stirring constantly until the onion begins to brown. Add smoked tomatoes (see our recipe for Smoky Tomatoes!), bay leaf, celery, thyme, salt, and pepper. Cook on low for about 40 minutes until the mixture thickens. Purée in a blender and serve over spaghetti.