broccoli soup

4 1/4 cups reduced sodium chicken broth, 1 medium onion, chopped 1 carrot, peeled and chopped 1 celery stalk, chopped 1 clove garlic, chopped 5 cups broccoli florets 1/2 cup 2% milk 3 tablespoons Greek yogurt ground black pepper to taste 1/2 cup sharp cheddar cheese (optional) . . In a medium sized stock pot, bring chicken broth, onions, carrots, garlic, and celery to a boil. Cover and simmer 5 minutes . . Add broccoli, milk and pepper and cook, covered, 10 more minutes . . Add sour cream and puree soup with an immersion blender . . Adjust black pepper to taste and heat through over medium heat, stir in the cheddar cheese a