Let me show you what a creamy prawn head soup you can make with them! You will love it.
Place the casserole over medium heat. Gently fry the ingredients for 3 minutes. Then add the prawn heads and shells.
Add the water, fish bouillon, tomato, chili powder (or chili paste) and tomato paste.
Bring the prawn soup to a boil. Then turn the heat lower and simmer for 20 minutes. Take the soup off the heat and let it cool down.
Then blend or mix the prawn soup until the ingredients are turned into a fine pulp. Pour the soup through a fine sieve (you can place a cheesecloth in it as well) over another large casserole and stir it until you end up with the shrimp pulp. Press well using the back of a spoon to get as many liquid out of it as possible.