Preheat oven to 220 c, 200 Fan, Gas 7. Or preheat grill if you don’t have an ovenproof frying pan and adjust cooking times on hob.
Whisk the eggs in a bowl with a pinch of salt and pepper. Add the parsley, Parmesan , lemon zest and juice.
Roughly chop half the prawns leaving the rest whole, and add all of them to the bowl.
Heat the butter with a splash of oil in a small non- stick ovenproof pan. When it start to foam add the egg mixture. Slowly move a spoon around the eggs for a minute or two on a medium heat then put the pan into the oven. Cook for 4-5 minutes until it has risen a bit and is slightly golden.