Bring a large pot of water to a boil, salt it, add the pasta and cook until al dente. Drain, reserving a couple of ladlefuls of the pasta cooking water.
While the pasta is working, in a large, heavy saucepan or Dutch oven, melt the butter over medium-high heat. Add the onion and garlic and cook until golden, 6 to 7 minutes. Stir in the wine for 1 minute, then the chicken stock. Add the broccoli, lemon peel, rosemary and crushed red pepper; season with salt and black pepper. Cover and cook for 10 minutes.
In a serving bowl, toss the pasta, reserved pasta cooking water, cooked vegetables, cheese and nuts for a minute. Season with salt and black pepper and serve, passing extra cheese at the table.