Heat a large saucepan over medium heat until hot. Add the oil and butter.
When hot but not smoking, add the onion and diced pepper. Sauté until the onion is translucent.
Deglaze the pan with the white wine or brandy and continue cooking until most of the wine has cooked off. This will add another layer of flavor.
Season the already cut up cooked chicken with some freshly ground pepper and add it to the pan to reheat for about one minute.
Add the half and half, nutmeg, parsley and peas being sure to mix together with a wooden spoon. Raise the heat to medium-high but as soon as the half and half comes to a boil, lower the heat to medium or medium-low and reduce the sauce to desired consistency (thickness).
When the sauce is just the way you like it, add some freshly grated cheese or try the crumbled up Roquefort.
Taste and adjust the seasoning with salt and pepper.
Drain the pasta but reserve a few tablespoons of the pasta water to add to the sauce if the sauce appears to be too thick. This thins out the sauce while giving it a little flavor from the cooked pasta.
Add the pasta to the saucepan; toss well and serve.