Beat the egg in a mixing bowl and mix the Parmesan cheese with the dried parsley, dried dill, onion and garlic powder, salt, and pepper in another bowl.
Dip the chicken into the egg and then into the Parmesan and seasoning mixture. Coat well.
Place the chicken breasts on a baking sheet and bake for 20-25 minutes.
Remove from the oven, top with the tomato sauce and shredded mozzarella cheese. Return to the oven for 10 more minutes until the mozzarella cheese is golden and bubbly.