Refreshing and nuanced, the elaborate Spanish-style "gin tonic" is one of our favorite drinks to enjoy on a balmy summer evening: oversize goblets with lots of ice and good-quality tonic, garnished with a host of botanicals that amplify those used in gin. To celebrate the brilliance of the baroque G&T, we're throwing a tapas party with four distinct variations on the cocktail—from muddled strawberries and black pepper to a savory variation with celery—and plenty of small plates, including patatas bravas, razor clams cooked in a garlicky white wine sauce, and padrón peppers with serrano ham.