In a large saucepan, preferably made of terracotta or enameled cast iron, sauté the chopped cured pork in the olive oil until the fat is translucent and the edges are just beginning to brown. Add the chopped onion, celery and parsley to the pot and give it all a stir, then season lightly with salt and pepper. Sauté the aromatics until the onion is quite soft and translucent. Add the tomato and let it simmer. If using the Parmesan rind, add it to the pot.

While the tomatoes are simmering, peel the potatoes and cut them into smallish cubes, adding the potato cubes to the pot as you go. When you're done, give everything a good turn, add a ladleful of water to moisten things, and cover. Let the potato cubes simmer for 1o minutes or so, until they are almost tender. In a separate pot or kettle, bring some water to the simmer.

Add the pasta to the pot, along with enough simmering water to cover the pasta entirely. Season with a generous pinch of salt, stir and cover the pot again. Let the pasta simmer over a moderate flame, stirring from time to time to prevent it sticking to the bottom of the pot, until done al dente. Ladle in more simmering water as needed to keep things soupy.

When things are just about done, add nice handful of grated cheese, to taste, and taste and adjust for seasoning. Add another ladleful of simmering water to the pot if it needs it—your pasta and potatoes can be served quite soupy or dry, as you prefer.