Place turkey drumsticks, water, celery, carrots, onions, parsley, cumin, bay leaves, peppercorns and salt into a large soup kettle and bring to a boil.
Skim scum from surface, lower heat to a simmer, cover kettle and simmer for 1 hour.
Strain through a china cap reserving both stock and turkey drumsticks, but discarding vegetables and herbs.
Return stock to kettle.
Remove turkey meat from drumsticks, discard skin and bones. Chop turkey into ¼-inch dice and reserve.
Bring turkey broth to a boil, add sweet potatoes, onions and poblanos. Return to a boil, reduce heat and simmer for 7 minutes.
Stir in red potatoes, tomatoes, corn, black beans, salsa verde, turkey base, blackened seasonings, liquid smoke and barbecue sauce.
Stir in reserved turkey.
Return soup to a simmer.
In a skillet, melt butter, add garlic and sauté for 2 minutes until softened but not brown. Stir in flour and continue to cook for 3 minutes to make a roux.
Whisk roux into soup.
Cook soup over a low heat stirring for 2-3 minutes.
Garnish each serving with a swirl of thinned sour cream and sliced scallions.
Yields: 6-1/2 gallons