In a large saucepan, melt butter. Add onion, carrot, celery, and garlic. Cook for 2 minutes. Add flour and cook until lightly browned. Set aside to cool. In medium saucepan, combine corn, chicken, and stock and bring to a boil. Simmer for 10 minutes. Whisk into the saucepan with the flour and vegetables. Bring to boil to thicken. Add coconut cream, nutmeg, and salt and pepper. Just before serving, add butter to the pot of soup.