Defrost the prawns. Clean, wash and drain the arugula. Wash and halve the tomatoes. Mix vinegar, salt, pepper and some sugar. Fold in the oil well.
Wash the parsley and chop finely. Whisk eggs, milk and half of the Parmesan cheese. Season with salt and pepper. Stir in parsley.
Rinse the prawns, pat them dry well and cut them into pieces. Heat the fat in a coated pan with lid (approx. 24 cm Ø). Fry the prawns briefly in it. Pour egg milk over them. Cover and allow to set for approx. 10 minutes over a low heat.
Slide the omelette onto a plate and put it back into the pan upside down. Continue frying for 3-5 minutes.
Cut the omelette into pieces. Mix salad and tomatoes with the marinade. Sprinkle with the rest of the Parmesan cheese. Arrange everything.