Combine the first three pesto ingredients (arugula, garlic and walnuts) in a blender or food processor and pulse to a coarse consistency.
Drizzle in the olive oil and continue to pulse/blend until the pesto is the consistency you prefer. I like it somewhere in between smooth and coarse. You can adjust the ingredients further to your tastes if you like.
Finally, either stir or process in the 2 tablespoons of parmesan.
Heat the 1 tablespoon of oil over medium heat and when hot, add the prosciutto, trying to keep it generally in a single layer as much as possible. Fry for about a minute, turn and fry an additional minute or until crispy. You can kind of visually tell when it’s there by the browning and how it's somewhat stiff when turning. Drain on paper towels.
Cook the pasta according to package directions until al dente and drain well. Fold in as much of the pesto as you like, then the prosciutto and the sun-dried tomatoes, if using.
Finally, garnish with parmesan cheese and EAT, baby, EEEEEAT!