Sort through the beans to remove any stones or damaged beans. Place the beans in a large plastic container with a lid. Add 2 Tbsp. salt and 10 cups water, stirring to dissolve the salt. Cover and let the beans soak for at least 8 hours or overnight.
Drain and rinse the beans, then transfer them to a 5- to 6-quart pot. Cover with 2 quarts of fresh water. Add the bay leaves and half of the chopped onion. Bring to a boil over high heat. Reduce heat to medium and cook, stirring occasionally and mashing some beans against the side of the pot with a wooden spoon, until the mixture begins to thicken, about 1 hour.
With about 15 minutes remaining on the beans’ cooking time, heat 1 Tbsp. oil in a large skillet over medium-high heat. Add the smoked turkey and cook, stirring occasionally, until it begins to brown, about 7 to 9 minutes. Using a slotted spoon, transfer the turkey to the pot with the beans.
In the same skillet over medium-high heat, heat the remaining 1 Tbsp. oil. Add the halal sausage and cook, stirring occasionally, until it starts to brown, about 7 to 9 minutes. Transfer the sausage to the pot with the beans using a slotted spoon.
Over medium heat in the same skillet, combine celery, bell pepper, and the remaining onion. Season with 1/2 tsp. salt. Cook, stirring occasionally, until the onions begin to soften, about 4 to 5 minutes. Add garlic and thyme, cooking while stirring until fragrant, about 1 to 2 minutes more.
Pour in the chicken broth to deglaze the pan, then add the mixture to the pot with the beans. Bring to a simmer and continue cooking, stirring occasionally, until the liquid thickens to the consistency of gravy, about 30 minutes. Remove and discard the bay leaves.
Serve the bean mixture over cooked white rice and garnish with chopped fresh parsley.