Pasta dishes are just always delicious!
Pluck the parsley leaves from the stems. Grind together with rosemary, garlic, 4 tablespoons olive oil, the pepper and walnuts in a food processor to a coarse paste. Blend as needed with the remaining olive oil until smooth, season with salt, and season with pepper. Bring a large saucepan to a boil, season with salt. Cook the pasta until al dente. Measure out a ladle of pasta water and set aside. Drain the pasta and transfer to a suitable bowl. Top with the rosemary pesto. Stir the pesto through with a small amount of pasta water as needed.
Serve with grated pecorino cheese.