Cover the dried beans with cold water and soak overnight.
Once the beans are soaked, melt 4 tablespoons of fat in a stockpot and saute the onion, green pepper, celery and garlic over medium high heat. Add the diced tomatoes with their juice and the 5-7 cups liquid to the stockpot. Drain and rinse the beans and add to the stockpot together with the red pepper flakes (or Harissa), thyme, bay leaf and ham hock. Bring to a boil, then reduce heat and simmer for 1 1/2 to 2 hours, adding more liquid, if necessary. Test the beans.
Heat 2 Tbsp of fat in a skillet and brown the sausages and ham. When browned, add to the beans, stirring in gently. Simmer for 20 more minutes until beans are tender but not mushy. Season with salt, pepper and Tabasco to taste.
Meanwhile, prepare rice. Bring 4 1/2 cups water to a boil, then add the rice and salt. Cover and cook over low heat for about 20--25 minutes, then remove from heat and keep covered.
Before serving, stir the chopped parsley into the beans and fold the butter into the hot rice. Present each separately to the table so each diner can choose their desired proportions.