Rich, nutty, bright, and sweet, romesco is another must-have sauce that will quickly and dependably elevate just about anything you take off the grill. First created in the Tarragona Province in Northwestern Spain, romesco is best known for being used to dunk giant grilled green onions called calçots during their annual harvest festival in between guzzling streams of red wine from a communal porrón. We encourage you to recreate that tradition, as well as enjoy this iconic and delicious red pesto with fish, vegetables, or dolloped over freshly steamed rice.