Made this chicken for my parents for dinner the other night, and it came out amazing! The chicken breasts I had were a little thick, and even after pounding them out thinner, they required a little extra cooking time. I just cut in to them a little to check for doneness before topping them with the mushrooms, cheese, and chives. Only substitution I made was Zesty Italian dressing since I didn't have balsamic! Make this, you'll love it!