Slow Cooker Seafood Gumbo

I adapted this recipe that was passed down to me by my family. –Donna

6 ribs celery, 4 left whole, 2 chopped
1 turkey carcass, bones from bone-in turkey breast (whole or half) with some meat attached, or 6 skin-on chicken pieces (2 backs and 4 wings)
1/2 pound beef sirloin, flank steak or flat iron, optional
1 each: trimmed, chopped, large onion, green pepper
1 can (14 ounces) chicken broth
2 cups water
3 tablespoon Creole seasoning, or to taste
2 bay leaves
1 can (28 ounces) crushed tomatoes
1/2 stick butter
1/4 cup flour
1-1/2 pounds okra sliced or 1 package (20 ounces) frozen cut okra
8 ounces, sliced smoked Chorizo sausage (Spanish not Mexican) or Polish sausage, sliced
12 ounces best available crabmeat
1 pint Gulf oysters, with liquor, any shell pieces removed
1-1/2 pounds shelled, deveined, medium to large shrimp
Cooked rice

Place 4 ribs of celery in the bottom of a slow cooker to serve as a rack; top with turkey carcass, chicken and beef, if using. Add remaining chopped celery, onion and green pepper. Add chicken broth and water. Season with 1 tablespoon of the Creole seasoning. Add bay leaves. Cook on LOW (50 percent) 6 hours.

When gumbo has cooked 6 hours, remove and discard any bones, skin, whole celery ribs.

Heat butter in a cast iron skillet over medium heat. Stir in flour. Cook, stirring, until mixture thickens and roux becomes the color of pecans, (careful not to form lumps) about 15 minutes. Gently stir roux into slow cooker. Add crushed tomatoes, okra, sausage slices, remaining 2 tablespoons of Creole seasoning. Cook on LOW (50 percent) until flavors come together, another 5 hours.