Soak the beans overnight in abundant water. In the morning, drain them and then replace the water so that they are covered by a few inches. Boil for 2 hours. (*If you are in a hurry, you can use canned white beans or cannellini beans)
Bring a large pot of salted water to boil for the pasta.
In a large skillet, sauté the onion, celery and garlic until translucent. Add the pancetta and cook over medium heat until the onions are golden, but taking care that the pancetta doesn’t get crispy. As described above, if you are starting with dry beans, drain them after the 2 hours of cooking (assuming they are tender) and then add them to the onion mixture. If using canned beans, add them now. Cook over medium heat for 5-10, making sure that the beans do not disintegrate. Cook the pasta, drain it and retain 1 cup of cooking liquid. Add the pasta to the beans. If the mixture seems dry, add some of the retained cooking water. Add black pepper to taste. Sprinkle with Parmigiano.
*2 hours with an overnight soak of the beans (45 minutes if using canned beans).