Broccoli Soup with Cheddar Crust

6 tablespoons butter, divided use
2 pounds broccoli, chopped into bite-size pieces, stems reserved
1 large onion, chopped
2 cloves garlic, chopped
1 teaspoon salt
1/2 teaspoon dried thyme
6 1/2 cups low-sodium chicken broth
1 cup whipping cream
3 tablespoons all-purpose flour
2 cups shredded cheddar cheese

1. Melt half the butter in a medium-sized, heavy-bottomed pot over medium-high heat. Add broccoli stems and onion; sauté until onion is translucent. Add garlic, salt and thyme and sauté for 1 minute. Stir in chicken broth and bring to a boil. Reduce heat and simmer until broccoli stems are tender, about 10 minutes; stir in cream (do not boil).
2. Mix remaining 3 tablespoon butter with flour in a small bowl until a paste is formed. Whisk paste into soup. Add broccoli florets to pot and cook over medium heat until soup thickens and broccoli is tender, about 5 minutes; stir frequently.
3. Preheat broiler. Place 6 ovenproof soup bowls on a low-rimmed baking sheet. Divide soup between bowls and sprinkle with cheese. Place under broiler until cheese melts and turns golden brown. Serve immediately.

Makes 6 servings.