Bring a large pot of salted water to a boil. Add the pasta and cook until al dente; drain, reserving 1 cup pasta cooking water and the pot.
Meanwhile, in a large nonstick skillet, heat 2 tablespoons olive oil over medium heat. Add the onion and cook until soft and golden, about 10 minutes. Stir in the garlic, then push the onion and garlic to the sides of the pan. Crumble the beef into the center of the pan, season with salt and pepper and increase the heat to medium-high. Cook, undisturbed, for 3 minutes, then stir to combine with the onions and garlic and cook until the meat is barely pink, about 2 minutes. Add the olives, 1/2 cup parsley and the reserved pasta cooking water and simmer for 1 minute.
In the reserved pot, combine the radicchio, remaining 1/4 cup parsley, the lemon peel, lemon juice and remaining 1 tablespoon olive oil; season with salt and pepper. Toss with the beef mixture and pasta. Drizzle with olive oil and season with salt and pepper.