Preheat the oven to 180 degrees Celsius.
Cut the prawns in half, lengthwise.
Butterfly prawns by cutting from the bottom of the prawn to the end of the head, being careful not to cut all the way through. This will help the prawns to open up and cook faster.
Move a fork back and forth to separate the shells and prawns.
Press butterflied prawns onto a lightly greased baking tray, with the cut side facing up.
Sprinkle a little bit of salt and pepper onto the cut side of the prawns.
Bake prawns for 5 minutes.
Take prawns out of the oven and drizzle a little bit of olive oil over the prawns.
Sprinkle grated parmesan, mozzarella cheese and grated cheddar cheese over the prawns.
Put prawns back into the oven and bake for a further 5 minutes.
Serving Suggestions: Garnish prawns with some finely chopped green onion and serve with a leafy salad.