First prepare the béchamel sauce: melt the butter in a saucepan, add the flour and mix, then add the already heated milk, then cook over a low heat, stirring constantly, until you obtain a thick but fluid sauce, then also add salt and walnuts. muscat.
Clean the prawns by removing the head, shell and casing (here is the guide on how to do it best).
Sauté the prawns in a non-stick pan with a little oil, blending them with the wine: a few minutes on high heat will be enough.
(If you have chosen to use lasagna that requires pre-cooking, first boil it in lightly salted boiling water, then drain it on a clean cloth.)
Assemble the lasagna: put a little bit of bechamel sauce on the bottom of the baking dish, add a first layer of pasta and cover it with another little bit of bechamel sauce.
Add a little prawns and pistachios and another little bit of béchamel and continue with the other layers until the ingredients are used up.
Complete the last layer with plenty of béchamel sauce and some pistachios, then cook for about 35-40 minutes in a preheated fan oven at 190°C.
The prawn and pistachio lasagna are ready, let them rest for at least 5-10 minutes before serving.