Spread softened butter on the outside of both bread slices.
Place one slice of bread, buttered side down, into a pan over medium-low heat. Layer the provolone on top, then add the second slice of bread, buttered side up.

Grill the sandwich slowly until the bread is golden brown, flip and continue grilling until the cheese is melty. Remove from heat and enjoy.

If you are packing this sandwich for later, let it cool before slicing it in half and packing it in a hard lunch container. Pack any sides like fruit or veggies in separate compartments. Use an ice pack if needed.