Preheat large pot over medium heat. Melt butter, then sauté onion, carrot and garlic for 5 minutes. Stir in mushrooms, salt and pepper and sauté another 5 minutes.
Pour in chicken stock, spices and salt and pepper to taste. Bring to boil, then reduce to simmer. Cook 15 minutes.
Puree to desired texture, then stir in half & half. Taste, adjust seasonings, then serve.