1. finely chop garlic with pine nuts in a food processor.
2. add pecorino, parmesan, arugula and oil, season with salt + pepper. Chop for about 5 sec. Open machine, blend down ingredients hanging on the side of the bowl, blend for 5-10 sec until smooth pesto.
Pour pesto into a large bowl, add 1-2 tbsp pasta cooking water and stir well.
Drain the pasta, add it to the pesto, mix well and serve on the spot. Serve with Pecorino or Parmesan cheese.