Shuck, scrub, and dry ears of fresh sweet corn, trim ends, brush with corn oil and grill or sear in a skillet. (Street stands use a salamander.) Skewer and set aside to cool. Make a paste with ½ cup mayonnaise and ½ cup hard grated cheese; if you don’t have cojita, Parmesan is fine, but a 50/50 mix of Parm and feta is better. Add a tablespoon of chili powder, add another and maybe a little salt. Spread the paste on the corn, and chill before serving.