Potato Parmigiana with Sausage and Porcini Mushrooms

Method

1. Slice the potatoes thinly (2-3 mm) using a mandoline or knife.
2. Blanch the potato slices in salted boiling water for 5-6 minutes. Alternatively, fry them in oil at 150-160°C for a crispier version.
3. Drain the potatoes and spread them on a clean kitchen towel to cool.
4. Prepare the besciamella: melt butter in a pot, add flour all at once, stir, and cook gently for 3-4 minutes. Gradually add warm or cold milk, whisking constantly to avoid lumps. Season with salt and a grating of nutmeg. Keep the besciamella slightly runny since it will cook further in the oven.
5. In a non-stick pan with a drizzle of olive oil, cook the sausage until browned, then add the porcini mushrooms (fresh or frozen) and sauté briefly.
6. Assemble the dish: spread a layer of besciamella on the bottom of a baking dish. Add a layer of potato slices, then sprinkle with rosemary, black pepper, and grated Parmigiano. Repeat with another layer of potatoes and continue for 3-4 layers total, finishing with a layer of besciamella and cheese on top.
7. Bake in a preheated oven until golden and bubbly.