Heat 1 tablespoon of the extra-virgin olive oil in a large skillet over medium-low heat. Roll the sausage into walnut-sized meatballs. Drop them into the skillet and brown on all sides, then remove them to a plate.
Heat the remaining 2 tablespoons extra-virgin olive oil in a large pot over medium heat. Saute the onion and garlic for 5 minutes, then add the escarole and season with salt, pepper, and nutmeg, to taste. Cook until the escarole has wilted. Add the beans and cook until heated through. Stir in the stock and bring to a boil, then add the pasta and cook to al dente.
Return the meatballs back to the pot for the last 4 minutes of cooking. Adjust the seasonings and ladle into serving bowls. Heavily sprinkle each serving with cheese and serve with crusty bread for mopping.