Bring a large pot of water to a boil, salt it, add the pasta and cook until al dente. Drain and return to the pot.
While the pasta is working, season the halibut with salt and pepper. Top each fillet with a sage leaf and wrap with a piece of prosciutto. In a large nonstick skillet, heat the EVOO, 1 turn of the pan, over medium heat. Add the fish and cook, turning once, until the fish is firm and the prosciutto is crisp, 8 to 10 minutes.
Add the butter, lemon juice and lemon peel to the pasta and toss. Serve with the fish.