The peppery bite of mustard greens creates a lovely contrast to pasta, and adding pancetta gives the whole dish a boost of flavor. Use bacon or prosciutto if you prefer, or skip the meat altogether for a lighter yet still delicious dish.
Place the oil and pancetta in a very large skillet and cook over medium heat until the pancetta is crisp, about 10 minutes. Add the red pepper flakes and garlic, and cook another minute, stirring constantly. Add the wine and mustard greens (it may be necessary to add them in batches), and cook until the greens are wilted and just tender, about 5 minutes. Season with salt and pepper to taste.
Meanwhile, bring a large pot of salted water to a boil over high heat; add the pasta and cook according to package directions until al dente (tender-firm). Drain the pasta, reserving 1 cup of the cooking water.
Add the cooked pasta to the skillet and toss with the greens mixture. Increase the heat to high and cook for 1 to 2 minutes, adding some of the reserved pasta water if the mixture seems dry.
Divide the pasta among 4 warmed shallow bowls. Sprinkle with some Parmesan cheese, if you like, and some of the pine nuts. Serve hot, with more Parmesan on the side.