Cook pasta as directed on package. Drain, reserving pasta cooking water.
Meanwhile, pulse lemon juice, herbs and shallots in food processor until almost a paste, scraping down side of bowl as needed. Add nuts, cheese and salt. Pulse until no whole nuts remain. With motor running, add oil in steady stream until well blended. Season with additional salt, if desired.
Transfer pesto to large deep skillet. Add 1 oz. pasta water and pasta. Toss until well coated, adding additional water as needed.
