Heat your outdoor grill to about 425-450° and coat the grates with vegetable oil. Put the peeled and de-veined shrimp in a medium bowl and coat with the remaining 1 tablespoon olive oil and salt/cardamom/pepper mixture. Thread each shrimp through the tail and head onto the skewers (5-6 shrimp per skewer) leaving about ⅛-inch space between each piece.