Whisk egg together and pour into shallow dish. Mix parmesan cheese, thyme and oregano together in a separate shallow dish. Working one at a time, coat chicken breast in egg and then cheese mixture. Put coated chicken breast in a casserole dish.
Spoon marinara sauce over each chicken breast. Top with shredded mozzarella.
Bake for 20 minutes or until chicken is cooked through and cheese is melted.