Directions:

Preheat oven to 325 degrees. Spread the walnuts in a shallow baking dish. Toast in the oven, shaking once or twice, until the nuts are lightly browned and fragrant, 5 to 7 minutes. Transfer to a plate and let cool. In a food processor, combine the olives, toasted walnuts, parsley, scallions, lemon juice and pepper flakes. Pulse, scraping the sides of the bowl occasionally, until the mixture is finely chopped. With the machine on, slowly pour the olive oil through the feed tube until incorporated. Toss in Parmesan cheese and pulse a few times. Serve the pesto at room temperature with pasta, crostini, bread sticks or crackers.