In a medium saucepan
, add the chicken thighs and cover with cold water by 1 inch. Bring to a boil, reduce the heat and simmer
until the chicken is tender, about 30 minutes. Strain
the chicken in a colander
, reserving the stock for later use. Let the chicken cool completely. Remove all the meat from the bones and discard the skin and bones.
Preheat the oven to 350 degrees F. In a large bowl, combine the chicken meat, shrimp
, sweet sausage, smoked sausage, rice, carrots, celery
, onion, seasoning salt, garlic powder, chili flakes and 2 quarts of the reserved chicken stock
. Pour the mixture into a 9-by-13-inch baking dish
. Cover and bake until the rice and shrimp are cooked through, about 25 minutes.