Cook your pasta based on the instructions. (I used fresh pasta pictured above)
Meanwhile, combine arugula, garlic, lemon juice, half of the cheese, pumpkin seeds, in a food processor. With the motor running, slowly drizzle in olive oil and process until evenly blended until finely processed. No more than a minute tops. Season well with salt (if using) and freshly ground black pepper.
Drain pasta and toss with the arugula pesto and mix until evenly combined. Serve immediately with reserved cheese sprinkled on top.