Meaty, flavor-packed olives require little effort to be transformed into a vegetarian no-cook “sauce” for pasta. We tame the bite of raw garlic and minced fresh chilies by steeping them in lemon juice, a combination that balances the olives' saltiness. You can use a food processor to pulse the olives until they're finely chopped or prep them by hand with a chef's knife—either way, make sure that the pieces are evenly fine so that they combine with the pasta rather than fall to the bottom of the bowl. Chopped baby arugula added at the end provides herbal peppery notes as well as verdant color. Pecorino Romano is a delicious flourish, but you could omit it to make the dish vegan.