1In 5-quart Dutch oven, heat oil over medium heat. Cook onion and garlic in oil until onion is tender. Add tomatoes and broth, breaking up tomatoes. Heat to boiling; reduce heat. Cover; simmer 15 minutes, stirring occasionally. Stir in pesto, whipping cream, salt and pepper with whisk until blended. Remove from heat. Cool 10 minutes. In blender, place half of soup. Cover; blend on high speed until smooth. Return to Dutch oven. Repeat with remaining soup.
2Sprinkle 1/3 cup cheese on each of 2 bread slices; top with remaining bread slices. Spread 1 tablespoon of the butter over one side of sandwiches. Place sandwiches, butter sides down, in 12-inch skillet. Cook over medium heat about 3 minutes or until bottoms are golden brown. Spread remaining 1 tablespoon butter over other sides of sandwiches. Turn; cook 2 minutes or until cheese is melted.
3Cut each sandwich into 6 squares. Place a grilled cheese crouton on top of each serving.