Grab the baking dish of your choice and spread a thin layer of bechamel sauce just enough to cover the bottom of the baking dish.

Now layer the pasta sheets on top of the bechamel sauce, covering the bottom of the dish.

Spread a layer of pistachio pesto evenly over the lasagna sheets, then arrange slices of mortadella on top of the pistachio pesto.

Lastly, add a layer of cubed fontal cheese on top of the mortadella.

Repeat the layers: lasagna sheets, bechamel sauce, pistachio pesto, mortadella, and fontal cheese, until you've used up all your ingredients. Make sure to finish with a layer of lasagna sheets on top.

For the final layer, spread a generous amount of bechamel sauce over the lasagna sheets, then dollop spoonfuls of pistachio pesto over the bechamel sauce, and spread it out evenly.

Sprinkle a generous amount of grated Parmesan cheese over the top layer of pistachio pesto, then the roughly chopped pistachios.

You're ready to put your pistachio lasagna in the oven to bake at 200C for 20 to 30 minutes, or until the lasagna is heated through and the cheese is melted and bubbly.