Beat eggs and lemon juice together and set aside. Heat 1 tbsp of the oil in a frying pan. Add broccoli and stir-fry for 2 mins. Add prawns, chilli and garlic and cook until the broccoli is just done. Tip everything out onto a plate and give the pan a wipe.
Heat a drop more oil in the pan. Pour in half the egg mix and swirl it around to make a thin omelette. Flip over to cook the other side, then lift onto a serving plate and keep warm. Quickly make another omelette. Add half the prawn mix to each, roll up and serve drizzled with some oyster sauce, if you like.