Creamy Winter Soup

Ingredients

• 1/3 cup butter, divided
• 1 pound chicken breasts, boneless, skinless, and cut into 1/2-inch pieces
• 1 small onion, chopped
• 1 medium carrot, shredded
• 1 rib celery, chopped
• 2 cloves garlic, minced
• 1/3 cup all-purpose flour
• 3 1/2 cups 2% milk
• 1 1/2 cups heavy whipping cream
• 1 tablespoon reduced-sodium chicken bouillon granules
• 1/4 teaspoon coarsely ground pepper
• 1 (16-ounce) package potato gnocchi
• 1/2 cup fresh spinach, chopped