Sprinkle the chicken pieces evenly with the salt and pepper. Heat the oil in a large stock pot over high heat. Add the chicken and brown on all sides, for about 4 minutes. Add the onions, bell peppers, celery, garlic, shallots, sausage and rice and stir fry for 2 minutes. Stir in the tomatoes, hot pepper sauce, bay leaves, essence and saffron and simmer for 1 minute. Add the stock, stir well and bring to a boil. Lower the heat, cover and simmer for 5 minutes. Add the clams, and cook for 5 minutes. Add the mussels and shrimp, cover and cook for 3 minutes. All of the clam and mussel shells should be opened. Discard any that are still closed.