Bring a large pot of water to a rolling boil and add a generous pinch of salt; cook the rigatoni until al dente according to package directions, reserving 1 cup of the pasta cooking water before draining.

While the pasta cooks, heat 1 tablespoon of the olive oil in a large skillet over medium-high heat. Add the cured pancetta or plant-based bacon substitute and pan-fry, stirring occasionally, until deeply browned and crispy at the edges, 6–10 minutes. Transfer the crispy pieces to a paper-towel-lined plate and set aside, leaving the rendered fat in the pan.

Lower the heat to medium and add the butter (or vegan butter) to the same skillet. When it melts, add the diced onion and a pinch of salt and cook until translucent and starting to brown at the edges, about 6–8 minutes. Add the minced garlic and cook for 30–60 seconds more, until fragrant.

If you like a slightly thicker sauce, sprinkle the tablespoon of flour into the onions and garlic, stir to coat, and cook for 1 minute to remove the raw flour taste.

Pour the white wine (or broth alternative) into the pan to deglaze, scraping up any browned bits from the bottom with a wooden spoon; simmer until the liquid is reduced by about half, 2–3 minutes.

Add the chicken or vegetable stock and bring the mixture to a gentle simmer. Stir in the cream (or coconut milk or cashew cream) and simmer for 2–3 minutes until the sauce is slightly thickened and glossy. Taste and season with salt, about 1/2 to 1 teaspoon depending on your saltiness preference and the saltiness of the cured pieces.

Lower the heat to medium-low. Add half of the grated cheese (or nutritional yeast if making vegan) and stir until melted and fully incorporated; the sauce should be silky and able to coat the back of a spoon. If it seems too thick, whisk in a few tablespoons of the reserved pasta water until it reaches a coating consistency.

Add the drained rigatoni to the skillet and toss to coat, finishing the pasta directly in the sauce over low heat for 1–2 minutes so the starch helps the sauce cling. Add lemon juice and a pinch of crushed red pepper flakes if using, then loosen with up to 1/2 cup of reserved pasta water to achieve the desired silkiness.

Plate the pasta in shallow bowls, spooning any extra sauce over the top. Scatter the crispy pancetta or plant-based pieces over each bowl, then crack coarse black pepper generously over the surface. Finish with the remaining grated cheese (or more nutritional yeast for vegan) and a sprinkle of chopped parsley. Drizzle with a teaspoon of olive oil if desired. Serve immediately.