This is my mum's Cantonese dried fried prawns with garlic we called gon jin ha look. Simple and so tasty. We always used very large king prawns (about 5 - 6 " long) and always with the shell and head on. Shells and heads are so good licking and sucking the sweet juice from the head. The garlic cloves are fried till light brown and very sweet.
Large raw king prawns can be expensive in the west. I normally get mine frozen from the Chinese supermarket about £10 - 12 /kg.