Let's begin with the pasta recipe: Sift the flour into a large bowl, then arrange it to form something similar to a volcano

Break the eggs (4) in the middle of it and whisk them together with salt and olive oil using a fork

Slowly fold the eggs into the flour, using your hands

Keep kneading the dough (vigorous movements using your palms!) for at least 10 minutes

Form dough into a ball, cover with a rag and let it rest for 30 minutes

Now, the filling: Cut leek into slices and sear it in a pan with butter

Stew potatoes, peel and mash them

Add parmesan, eggs (2), leek, salt and pepper to the mashed potatoes: stir until homogenous

Let the filling rest for 60 minutes in the fridge

Let's begin making ravioli! Cover in flour a flat surface and roll out the dough to form a very thin rectangle (2mm or 1/12"), you can use a pasta machine if you have it

Along the longer side of the rectangle, on the upper part of it, put a teaspoon of filling every 4cm or 2"

Cover the filling with the lower part of pasta of the same rectangle, press on the edges to bind the two layers of pasta

Cut ravioli with a ravioli stamp or a cog

Put the ravioli you cut on a tray covered in flour so they not stick together

They are now ready to be boiled (just few minutes) and mixed with your favorite sauce! You can also freeze them to use it whenever you want!