This Grilled Cheese’s Secret Ingredient? Guacamole
“Of all the cheeses out there, the amount you can put inside of a sandwich that will melt well is very small. You can really only work with cheeses that are going to melt and be gooey in a couple minutes. And we like to stick with cheeses that people are pretty familiar with. The cheese has to be good on its own, and then we find ingredients that match that cheese, rather than the opposite.