Bring a large pot of water to a boil and add enough salt to make the water taste like the sea.

When it comes to a boil, add the pasta, return the water to a boil, and cook the pasta until al dente, stirring occasionally to prevent the noodles from sticking, usually 3 to 4 minutes for fresh pasta, or about 9 to 10 minutes for dried pasta. When the pasta is done, drain it in a colander, reserving about 1/2 cup of the pasta cooking water separately.

Meanwhile, while the pasta is cooking, melt the butter and the oil in a large skillet over medium heat.

Add the pancetta or ham, if desired, and cook, stirring, for 3 minutes, or until the fat has mostly rendered from the pancetta.

Add the onion and cook, stirring, for 2 minutes.

Add the garlic, and cook, stirring, for 30 seconds.

Add the heavy cream and bring to a boil. Cook until the volume is reduced by half, about 5 minutes. If desired, add the peas. Add the teaspoon of salt and the pepper, and stir well.

Place the drained pasta in a large, heatproof bowl and add the sauce. Toss to coat well, using a bit of the pasta water if the sauce is too thick -- this will help the sauce adhere to the pasta.

Add the cheese and toss to coat.

Serve immediately, garnished with more cheese if desired and a sprinkling of freshly ground black pepper.