A simple onion-y sauce makes this spaghetti spectacular.
Bring a large pot of water to a boil for the pasta.
In a large skillet, heat the EVOO, four turns of the pan, over medium to medium-high. Add the fennel and onion; season with salt. Cook, partially covered, stirring occasionally, just until the vegetables soften (do not brown), 6 to 7 minutes. Add the garlic; stir for a minute. Stir in the fennel pollen, crushed red pepper, and lemon zest, then add the wine and broth. Cook until the sauce is reduced by half, 8 to 10 minutes. Stir in the cream and reduce the heat to a simmer while you cook the pasta.
Salt the water, add the pasta, and cook about 1 minute less than the package directions. Reserve 1/2 cup cooking water. Drain the pasta.
Add the pasta, lemon juice, pasta cooking water, and cheese to the sauce; toss to coat. Serve the pasta topped with the parsley, nuts, and fennel fronds.