In a large mixing bowl, combine the shrimp, sliced sausage, diced bell peppers, chopped onion, and minced garlic.
Drizzle the olive oil over the mixture, then sprinkle in the Cajun seasoning, salt, and pepper. Toss everything together until well coated.
Cut four large pieces of aluminum foil (about 12x18 inches each). Place an equal amount of the shrimp and sausage mixture in the center of each piece of foil.
Fold the sides of the foil over the mixture, then roll the ends to seal the packets tightly. Make sure they are well sealed to prevent any juices from leaking out during cooking.
Place the foil packets on the grill or in the oven. Cook for 15-20 minutes, or until the shrimp are pink and cooked through.
Carefully open the packets (watch for steam!) and garnish with fresh parsley.
Serve with lemon wedges on the side for an extra burst of flavor.
Notes
Serve packets directly on a plate for a fun dining experience.