Put the beans, salt and pepper into a food mill set over a large bowl and run them through, or use a food processor to mash them as smooth as possible. You should have about 2 cups.
Using a fork to stir, add the cheese, egg and nutmeg. Add half the flour and stir, slowly adding more flour until it starts to form a dough you can handle… but just barely.
Turn the dough out on a lightly floured surface. Knead very gently for a minute or so. At this point you want to test the dough to make sure it holds its shape when cooked. Put some water on to boil in a small pot. Pinch off a small piece of dough, the size of a large grape, and drop it into the boiling water. If itdoesn’t hold it shape add a little more flour to your dough and knead it in gently.
Divide the dough into four pieces. Roll each piece into a rope about 1/2 inch thick on a lightly floured surface. Cut each rope into 1 inch pieces.
Your gnocchi are ready to cook. You could place them on a lightly floured sheet pan, separated and not piled on top of each other, to freeze them for another time.
To cook, fill a large pot halfway with water, add 1 tsp salt, and bring to a boil. While waiting for the water to boil get ready a slotted spoon for removing the gnocchi from the water and lightly butter a serving dish. When the water is boiling drop in some of the gnocchi, I did mine in 3 batches. The gnocchi will sink to the bottom and when cooked they will rise to the surface. They only take 2-3 minutes to cook. Remove with the slotted spoon and place on your prepared dish. Sprinkle with Parmesan cheese, or serve with pesto or tomato sauce, or try them in tomato basil soup.
Note: Cannellini beans are creamy, white Italian beans, sometimes called white kidney beans. You can buy dry beans and soak and cook them yourself, or use canned beans.
Adapted from How to Cook Everything Vegetarian by Mark Bittman