Preparation

• 1
  Defrost the prawns if frozen, or wash and pat dry if chilled.
• 2
  Wipe then halve the baby button mushrooms.
• 3
  Preheat the oven to 200 degrees, 180 degrees fan oven.
• 4
  Heat 15g of butter in a small frying pan over a low heat and cook the mushrooms gently for 3-4 minutes. Stir in the prawns, heat through for a minute or two and then remove from the heat.
• 5
  Make a bechamel sauce. Melt 20g of butter in a saucepan, stir in the flour and then gradually stir in the milk until really smooth. Cook gently and stir for 2 minutes, add a grating of nutmeg and season with salt and black pepper.
• 6
  At the same time, cook the pasta until it is almost al dente, drain well and then return to the warm pan, off the heat.
• 7
  Stir the mushrooms and prawns into the bechamel sauce and heat through. Stir into the pasta. Grate in half of the parmesan cheese and stir in 1-2 teaspoons of lemon juice, to taste.
• 8
  Cut the mozzarella cheese into small pieces and grate the rest of the parmesan.
• 9
  Into two gratin dishes, spoon half of the pasta and sprinkle on half of the parmesan. Cover with the rest of the pasta and a final layer of parmesan. Scatter on the mozzarella, add a grinding of black pepper and then bake for 20 minutes until golden