The word güveç (pronounced ‘goo-wetch‘) means a clay pot in which traditional casseroles are made. The usual version of karides güveç, served in restaurants and meyhanes in Turkish coastal cities, uses small prawns or shrimps, but because I live in Australia, I have the luxury of easy access to prawns of significant size. Using bigger prawns also saves shelling time.
The mushrooms keep the casserole moist when it’s cooking, and help prevent the prawns from drying out. You need only bake the güveç in the oven for long enough to let the haloumi melt, without overcooking the prawns.