Stock:

• 1 turkey carcass
• 1 large onion, halved and skin left on
• 1 large carrot, roughly chopped
• 1 stalk celery, roughly chopped
• 1 head garlic, halved
• 1 teaspoon dried rosemary
• 1 teaspoon dried thyme
• 2 bay leaves
• salt and ground black pepper to taste
• 2 quarts water, or as needed

Soup:

• 2 large onions, diced
• 2 carrots, diced
• 2 stalks celery, diced
• 2 cloves garlic, minced
• 1 teaspoon poultry seasoning
• 1 teaspoon dried rosemary
• 1 teaspoon onion powder
• 2 cups cooked rice
• salt and ground black pepper to taste

1. Make stock: Combine turkey carcass, onion, carrot, celery, garlic, rosemary, thyme, bay leaves, salt, and pepper in a stockpot; pour in enough water to cover. Bring mixture to a boil, cover the pot, reduce heat, and simmer until flavors have blended, about 1 hour.
2. Remove turkey carcass and pull remaining meat from bones; reserve meat and discard carcass. Use a slotted spoon to remove and discard vegetables and bay leaves.
3. Make soup: Stir onions, carrots, celery, garlic, poultry seasoning, rosemary, and onion powder into stock; bring to a boil. Reduce heat, cover the pot, and simmer until vegetables are very tender, 20 to 30 minutes.
4. Add cooked rice and reserved turkey meat to soup; season with salt and pepper. Cook until rice and turkey meat are warmed through, about 5 minutes.