Fill a stockpot halfway with water. Add the Zatarains, onions, and garlic and bring to a boil. Add the sausage and simmer over medium-high heat for 5 minutes. Add the peppers and corn, bring back to a boil, and add the shrimp. Cook until the shrimp are pink, about 3 to 4 minutes. Strain. Serve with cocktail sauce, saltines, bread, and salad.