Preheat oven to 350 degrees F.
Scrub potatoes, pierce the skin with a fork, drizzle with olive oil and salt and place on a sheet pan. Place the sheet pan in the oven and bake for 45 minutes to 1 hour until they are easily pierced with a pairing knife. Allow the potatoes to cool slightly then peel the potatoes while they are still hot and press them through a potato ricer. Put the potatoes in a large bowl with salt, nutmeg, baking powder, grated cheese and egg white. Add the flour a little at a time and mix with your hands until the mixture forms a rough dough. Do not over-work the dough. Transfer the dough to a lightly floured surface. Gently knead the dough for 1 or 2 minutes until smooth, adding a little bit more flour, if necessary, to keep it from sticking.
Break off a piece of the dough and roll it back and forth into a rope, about the thickness of your index finger. Cut the rope into 1-inch pieces. Gently roll each piece down the prongs of a fork while pressing a small dimple with your finger in the back. The gnocchi should be slightly curved and marked with ridges. This will allow the pillows to hold sauce when served. Cover with plastic wrap and refrigerate for up to 12 hours.
Boil the gnocchi in batches in plenty of salted water. The gnocchi are done about 2 minutes after they float to the surface, remove with a slotted spoon. Reserve about 1/2 cup cooking water. If not cooking immediately, place the gnocchi in a single layer on a baking pan dusted with flour.
Note: If the gnocchi start to feather and fall apart in boiling water, you need more flour. If the gnocchi don't float after 2 minutes and are hard, you used too much flour.
Blanch peas in hot water and set aside.
Place 4 strips of prosciutto on a sheet pan and place in a preheated 350 degree F oven. Cook until the bacon is crispy, 8 to 10 minutes.
Add chopped shallots to a pan over medium high heat with 2 counts of olive oil pan of and gently saute until fragrant and translucent. Dump in the peas and toss gently to coat. Season with a little salt and pepper. Add boiled gnocchi to the pan and gently toss. Add a ladle of gnocchi water to the pan, add 1 tablespoon of butter, sprinkle with Parmesan and season with salt and pepper. Serve topped with crispy prosciutto and a scoop of fresh lemon ricotta. (Optional: finish with a drizzle of white truffle oil)
Place the ricotta cheese in a mixing bowl and add the lemon zest and juice. Season with salt and serve with the gnocchi.
Yield: 4 to 6 servings