There are many variations of the recipe, all of which involve a cutlet, cheese, and meat. A popular way to prepare chicken cordon bleu is to butterfly cut a chicken breast, place a thin slice of ham inside, along with a thin slice of a soft, easily melted cheese such as Swiss. The chicken breast is then rolled into a roulade, coated in bread crumbs and then deep fried. Other variations exist with the chicken baked rather than fried.

What kind of cheese is in chicken cordon bleu? Let's have some stream of consciousness first.
The relevant information to answer the above question is: A popular way to prepare chicken cordon bleu is to butterfly cut a chicken breast, place a thin slice of ham inside, along with a thin slice of a soft, easily melted cheese such as Swiss. So, the answer is a thin slice of a soft , easily melted cheese such as Swiss.