Mix meat, ricotta, and spinach together in a bowl.
Form small meatballs from the mixture and set them aside.
Mix flour and salt well on the table. Gather the flour and make a well in the middle the size of a clenched fist.
Crack 2 of the eggs into the well and also pour in the oil.
Lightly beat the eggs with a fork. Gradually beat the flour into the eggs while continuing to beat with the fork. Continue until the fork can't beat anymore, then continue kneading with your hands until the dough is firm and elastic. Knead for approximately 15 - 20 minutes.
Put the dough in a bag and let it rest in the refrigerator for 30 minutes.
Pour the dough onto a floured surface.
Dust the dough with flour before rolling it through the pasta machine. Continue to roll the dough through the machine until it has a thickness of 2 millimeters. Continually dust the pasta dough with flour to prevent it from sticking to the machine.
Cut circles in the thin pasta dough with a cutter 10 centimeters in diameter.
Place a dollop of ravioli filling in the center of half of the pasta circles.
Beat the remaining egg in a glass/bowl and brush the edges of the pasta circles with filling. Use very little egg so the pasta does not become too wet – it should only bind the two pieces of pasta together.
Place a piece of pasta on top and gently press the edges together while also pressing out the air so the pasta closes completely around the filling.
Boil the ravioli for 4 minutes in lightly salted water (1 tablespoon of salt per 1 liter of water) and also add a tablespoon of olive oil to the water.
Boil down the stock/broth over medium-high heat for a couple of minutes in a sauté pan. I used chicken stock, but duck or beef can also be used.
Add white wine and let it boil down for a few more minutes.
Add the cold butter bit by bit under whisking. Let it thicken slightly.
Remove the cooked ravioli and place them in the pan with the pasta cooking water.
