Soak the beans the day before if they are dry. Boil them for an hour, drain andset them aside
Pour the flour on the pastry board and create a dough with warm water and a pinch of salt, until a firm dough is obtained.Once the dough is made, make thin sheets; roll out the pasta by hand and cut the sagne into the shape of strips one cm wide and five in length. Put them on a tray, dust them with flour to prevent them from sticking, and let them rest.
Slice the onion and coarsely chop the celery, put together with the oil and tomato and saute for 20 minutes till thick. Add the beans and a ladle of water; leave to gently simmer for 10 minutes before leaving to sit.
Once the sauce is cooked, bring the water to a boil, add salt, and cook the sagne for 4/5 minutes, stirring often.Drain, reserving the pasta water, and add the sauce to the sagne pasta in the pan, Add up to 2 ladles of the pasta cooking water to ensure the sauce is light and fully dresses the pasta. Serve hot with peperoncino