In the meantime, prepare the filling: put the ricotta in a container, add the boiled and cut chard, along with the grated Parmigiano Reggiano, egg and salt and mix everything together with the grated nutmeg.
Roll out the pasta with a rolling pin to obtain a thin sheet. Place the pasta on a work surface and place a teaspoon of filling (for each tortello) on top and then cover it with the pasta, try not to leave any air holes that could cause the tortello to break up during cooking.
Prepare a dish that has some knobs of butter on the bottom, place the well-draned tortelli on top and cover with a layer of Parmigiano Reggiano on top.
First prepare the meat sauce: take a saucepan and melt the butter in it, then add the bacon, celery, carrots and onions (all chopped up finely), add the minced beef, red wine, tomato sauce, meat broth, whole milk, salt, pepper and grated nutmeg; mix thoroughly and leave to simmer over a low heat for 2 hours.
Then, make the home-made pasta: take the all-purpose flour, make a well in the centre and break two eggs into it, then start mixing everything by kneading. Rest the pasta for 30 minutes.
Roll out the pasta with a rolling pin to obtain a thin sheet. Then, cut the pasta into strips to make tagliatelle.
Place a pan of salted water on the stove and bring it to the boil. When boiling, add the tagliatelle and stir; drain after 5 minutes.
Take a frying pan and toss the tagliatelle in it with the ragout for a couple of minutes.
When the tagliatelle are ready, server them with grated Parmigiano Reggiano.