In a 6 quart saucepot, ... celery, green pepper, onion, thyme, salt and pepper. ... smooth. Stir into soup. Stirring over medium-high heat, ... in butter until melted.
(A flavorful addition is chopped ... low heat. Add onions and thyme and cook 10-12 ... are tender. Puree soup in batches in a blender ... so soup doesn't scorch.