Defrost the frozen shrimps. Clean, wash and drain the arugula well. Peel the radish. Wash apples and remove the core with an apple corer. Slice apples and radish into very thin slices.
Drizzle apple slices with lemon juice.
Peel prawns down to the tail fin. Carve lengthwise on the back and remove the dark gut. Wash shrimps and dab dry. Heat 1 tablespoon of oil in a coated pan. Fry the prawns for 3-4 minutes.
Season with salt and pepper.
Finely slice or grate the cheese. Mix vinegar, mustard, salt, pepper and 1 pinch of sugar. Fold in 2 tablespoons of oil. Arrange the radish and apple slices in flakes on four plates. Arrange rocket salad and prawns on top.
Drizzle with marinade and sprinkle with parmesan.