Preheat the grill for indirect cooking at 250 F. Add your wood or pellet flavor of choice and get it smoking!
Over medium high heat, place your cast iron skillet on the burner and melt the 2 sticks of butter. Remove it from the heat and place it on a cooler burner.
Add in the garlic and then mix in the Worcestershire sauce, Tabasco, lemon juice, and Cajun BBQ seasoning.
in the shrimp so they are fully coated in the butter mixture. Then lay them flat in the pan so they can cook evenly.
Cook them for 30-45 minutes depending on the size of your shrimp (small shrimp will cook faster than larger shrimp). The internal temperature should register to 145 F. and the shrimp will no longer be translucent.
Sprinkle the shrimp with fresh parsley and red pepper flakes and serve as desired.