If you're wondering what to do with your Thanksgiving leftovers, try this satisfying soup. It's great with dried pasta, but I think it's even more compelling with my Granmaw Hartle's soft, fluffy potato dumplings.
For the soup: Bring the broth to a simmer in a large stockpot. Heat the olive oil over medium-high heat in a medium stockpot. Add the turkey neck, gizzard, heart, and wings and brown. Add the onion, ginger, carrots, celery, and garlic and cook until aromatic, 1 minute. Add sherry vinegar and cook until almost dry.
Ladle the broth over the vegetable/turkey mixture and lower heat to allow the stock to simmer for 30 minutes.
For the dumplings: Preheat oven to 375 degrees F. Lightly coat the potatoes with oil, sprinkle with salt and pepper, then wrap in aluminum foil. Bake until tender, about 90 minutes. Peel the baked potatoes, then pass through a ricer into a bowl. Beat the egg, make a well in the potatoes, and gradually incorporate. Add the baking powder and half of the flour and continue to gently mix until the flour is absorbed and the dough comes together. Cover bowl with a kitchen towel and let rest for 10 minutes.
While the dumpling dough is resting, strain the stock into a separate stockpot and bring back to a simmer. Add half of the soy sauce, a couple pinches of salt, sweet potatoes, butternut squash, radish, rosemary, and thyme; simmer 10-12 minutes.
While the soup is simmering, fold in the remaining flour and Gruyère to the dumpling dough; rest the dough again for one minute. Add the cauliflower, leftover turkey, remaining soy sauce, and a pinch of salt to the simmering soup.
Turn the dough onto a floured work surface and roll out to a rectangle about ¼-inch thick; cut into rough squares. Place dumplings into the simmering broth to cook for 3 minutes (when they're fully cooked, they'll rise to the surface). Adjust seasoning for salt, garnish with parsley, and serve.