Preheat oven to 375 F. Coat a baking dish with a thin layer of olive oil.
Place chicken breast inside a ziploc bag and pound with a meat mallet until breast is about 1/2" thick. Don't pound too long or hard, or the breast will start to fall apart. Cut slits across each breast about 1/2 through.
Mix mayo, Montreal seasoning, paprika, and garlic powder. Then stir in grated parmesan. Spread evenly over tops of chicken breasts.
Bake chicken for 35 to 40 minutes, until internal temp is 165 F. Since there will be some liquid at the bottom of the baking dish, transfer the chicken to a serving dish. Squeeze juice from half lemon over chicken breasts.
