How to Make It
In a large, deep skillet, melt the butter in the oil. Add the pancetta and cook over moderate heat, stirring frequently, until crisp and browned, about 7 minutes. Using a slotted spoon, transfer the pancetta to a plate.
Add the onion to the skillet and cook over moderate heat, stirring occasionally, until softened and just beginning to brown, about 7 minutes. Add the cabbage, thyme and nutmeg and season with salt and pepper. Cook, stirring occasionally, until the cabbage is very tender and just beginning to brown, about 20 minutes. Stir in the mascarpone and keep warm.
Meanwhile, bring a large pot of salted water to a boil. Add the pasta and cook until al dente; drain, reserving 1 cup of the cooking liquid. Add the pasta and cooking liquid to the cabbage and cook, stirring, until the liquid is absorbed and the pasta is coated in a lightly creamy sauce, about 1 minute. Stir in the pancetta and serve right away.