Mozzarella's more sophisticated cousin is sharp but not too sharp, melty but not runny, and firm but malleable. There's a reason it's a mainstay on deli sandwiches and cheesesteaks alike, and you should absolutely be giving it a starring role in your grilled cheese lineup, regardless of whether said sandwich includes warmed-up Italian cold cuts.
"We use it because it's very recognizable," says Fish. "It adds stability to the sandwich and it looks good, so there's high appeal there."
2. Pepper Jack
You want a neutral cheese? Go back to Switzerland (no, wait, Swiss cheese doesn't work that way). Pepper Jack's one of the most flavorful, aggressive cheeses out there, and one that's guaranteed to step your sandwich up a notch without requiring you to get crafty and add flavoring.
"This one adds much more flavor profile than American or provolone. There's different heat levels, too -- we've used habanero and jalapeño pepper Jacks before," says Fish. "If you're looking to add a slight heat element, it's great."