How to Make It
Melt butter in a medium saucepan over medium. Add onion, carrot, and garlic; cook, stirring occasionally, until tender, about 15 minutes. Coarsely chop 4 ounces of the cheese; shred remaining 1 ounce cheese, and set aside. Add chopped cheese, tomatoes, broth, and salt to onion mixture; bring to a simmer. Cover and cook 20 minutes. Carefully transfer soup to a blender; remove center piece from blender lid, and cover with a clean towel to vent. Process until very smooth, about 1 minute. Divide evenly among 6 bowls, and sprinkle with shredded cheese and basil.