In a mixing bowl, combine shrimp, oil, minced garlic and salt. Mix well to evenly coat shrimp. Using a piece of foil folded in half, place half of the shrimp onto the foil in the center.
Pull opposite ends to the center to join and roll down to seal. Tuck the ends up to seal as well. Leave a pocket inside to steam the shrimp. Repeat with the remaining shrimp so you have 2 foil packets.
Heat grill to about 400 F. Place packets onto the grill and cook for 15-20 minutes or until shrimp is pink and no longer frozen.
Open packets and season with ground black pepper and red pepper flakes if desired for a bit of heat. Serve topped with chopped fresh parsley and fresh lemon wedges