Melt your butter in a large Dutch oven or stock pot.
Add the carrots, onion, and celery to the pot, season with salt and pepper, and cook until softened, about 5 minutes.
Add the mushrooms and garlic and cook another 5 minutes.
Add the flour and cook about 3-5 minutes.
Add 4 cups of the turkey or chicken stock, thyme, rosemary, Worcestershire sauce, and rice.
Bring to a simmer and then cover and simmer for 30 minutes.
Add the sherry and turkey and simmer, uncovered, another 15-20 minutes, until the rice is cooked.
Stir in the half and half and slivered almonds.
Taste and add salt and pepper as needed.
Add more stock if soup is too thick for your liking. Enjoy!