1Melt butter in 6-quart Dutch oven over medium-low heat. Cover and cook garlic, celery, carrot and onion in butter 10 minutes, stirring occasionally.
2Stir in broth and water. Heat to boiling; reduce heat. Stir in tortellini. Cover and simmer about 20 minutes, stirring occasionally, until tortellini are tender.
3Stir in parsley, pepper and nutmeg. Cover and simmer 10 minutes. Top each serving with cheese.