Poke the red potatoes twice with a fork and place them in the microwave. Cooking time will vary depending on the size of your potatoes but I usually do 4 to 5 minutes. This allows the potatoes to start cooking and will ensure they are fully cooked when you remove them from the grill.
Take a square piece of heavy duty foil and place the shrimp, corn, and potatoes in the center. Add in a Tbsp of butter, and then sprinkle a Tbsp of the seasoning mix. Cover the ingredients with the foil and seal packet.
Place on heated grill and cook for a full 20 minutes.
Carefully remove from the grill and keep foil wrapped tightly until you are ready to serve.
Notes
When your foil packet is done cooking it will have steam in it, so be very careful opening it!