Pre-heat a medium skillet over medium heat for five minutes. 

Shred the two cheeses and mix them together. 

Butter one side of one piece of bread and place it in butter side down in the skillet. Add mayonnaise to the exposed side of the bread that is in the skillet. 

Add cheese in a fairly even layer to the top of the slice of bread in the skillet. 

Cover skillet with lid or a piece of aluminum foil. This will help the cheese to start to melt. Cook for 3 minutes. 

Spread mayonnaise on your second slice of bread while the cheese is melting. 

After the three minutes are up, remove lid and add 1 to 2 tablespoons of chili crisp on top of the cheese.

Add second slice of bread mayonnaise side down on top to sandwich everything.

Spread butter on the top slice of bread and flip the sandwich. 

Cook for another 3 minutes on the second side. If the first side didn't get toasted enough to your liking, you can continue cooking and flipping occasionally until both sides are toasted well. 

Serve and enjoy.