***For stock*** 1 carcass from roast turkey or roast chicken 3 quarts water, or as needed 1 large yellow onion, chopped 2 carrots, peeled and chopped 1 celery stalk, chopped 4 fresh flat-leaf parsley sprigs 1 bay leaf ***For Soup*** 8 cups turkey stock 1 1/2 cup chopped yellow onion 2/3 cup peeled and diced carrot 1/2 cup diced celery 2 teaspoons chopped serrano or jalapeno peppers (or to taste) 1 cup cooked long-grain white rice 2 cups diced cooked turkey or chicken salt and freshly ground pepper, to taste 1/4 cup chopped fresh flat-leaf parsley (optional)
Place carcass (breaking it up to fit) in crockpot with onion, carrots, celery, parsley and bay leaf with water to cover.
Cook over high heat for 1 hour, skimming off any foam that forms on the surface. Cover and continue to cook over low heat for 8-10 more hours, skimming as needed.
Strain turkey stock and discard all solid ingredients. Refrigerate broth, uncovered, until chilled, about 6 hours or overnight, then lift off and discard the fat solidified on top.
Place stock and all vegetables in a crockpot and cook on low heat for 6-8 hours.
Add turkey and rice and cook for an additional hour.
Season to taste with salt and pepper and garnish with the parsley, if desired.