Preheat the oven to 400F. Grease a baking sheet with cooking spray and set aside.
In a bowl, whisk together an egg, lemon juice, garlic, and salt. Place the chicken in the egg mixture and marinade in the refrigerator for 30-60 minutes. You can skip this step, if necessary.
Wash and quarter the potatoes. Wash, trim, and cut fresh green beans into thirds. Pour half of the butter mixture over the potatoes and the other half over the green beans. Toss to coat.
In a bowl, mix breadcrumbs and Parmesan cheese. Dredge the marinaded chicken in the breadcrumb mixture, making sure the crumbs stick to the chicken, pressing if needed.
Place chicken and potatoes on a cooking sheet, arranging the potatoes around the chicken in a single layer.
Bake in the oven for 15 minutes.
Remove the baking sheet from the oven and flip chicken. Move the potatoes to one side and place the green beans around the chicken.
Turn the oven to broil. Return the baking sheet to the oven and broil for 10-15 minutes. The chicken should be cooked to 165F, golden, and crispy. The potatoes and green beans should be cooked though.
Sprinkle with fresh chopped parsley and serve.
