I'm honestly not sure how they're cooked - but not boiled or fried. Sort of teriyaki style. I would say sort of a combo of grilled/stir-fried/steamed in the butter garlic sauce. At home I do something similar that is called bbq shrimp and is baked in the oven. They are pretty large shrimp you pick up by the tail and eat, so it involves using your hands and getting a little sticky.