Par cook the potatoes by microwaving them for 5 minutes; carefully transfer to a large mixing bowl. Add the shrimp and corn to the bowl. Sprinkle with Old Bay and toss gently to combine. 

Arrange 4 large squares of heavy duty aluminum foil on a baking sheet. Place 1/4 of the mixture on the center of each sheet. Top with a heaping teaspoon of ghee or butter, then fold each foil sheet into a packet by bringing two opposite sides together. Crimp the remaining sides before bringing them up over the top and sealing well. 

Place the foil packs seam-side up on a hot grill. Grill for 10-15 minutes, turning once, or until the potatoes are soft and the shrimp is cooked through.