1/4 teaspoon fresh ground pepper, plus more to taste
Bring a large stockpot of salted water to a boil. Stir in orzo. Cook until tender, about 10 minutes, or follow package instructions. Drain in a colander, and set aside. Bring a large saucepan of salted water to a boil. Prepare an ice bath. Blanch arugula in boiling water until bright green in color, 5 to 10 seconds. Immediately transfer arugula to ice bath to stop the cooking process. Drain, and squeeze out any excess water. Place arugula and garlic in the bowl of a food processor. Using the feed tube, slowly add olive oil while pulsing machine on and off. Add 1 teaspoon salt and pepper; process until pureed. Transfer orzo to serving bowl, and toss with arugula puree. Season with salt and pepper.