Holding sharp knife parallel to the cutting board, slice chicken in half horizontally, taking care to keep both pieces of chicken uniform in size and about 1/2-inch thick. Alternately, place chicken between two pieces of parchment paper or inside of a zip top bag and pound with an iron skillet until the chicken is about 1/2-inch thick. Once all chicken has been prepared, place onto a piece of parchment paper and dust both sides liberally with all-purpose flour.
Pour buttermilk into a flat, deep dish for dredging chicken.
Prepare Herbed Buttermilk Biscuit Breading by placing all ingredients listed for breading into a food processor or blender and pulsing until fine bread crumbs have been made. Pour into another flat, deep dish for the next step in dredging.
Dredge the chicken by first dipping into the buttermilk, then into the biscuit breading. Place onto a sheet pan and repeat until all chicken has been breaded. Allow to rest for about 10-15 minutes before frying.
Heat 1 cup of olive or vegetable oil in a 12-inch skillet over medium heat. Once the oil begins to sizzle when you drop in a drop of water, it is ready to cook the chicken.
Fry chicken on each side for about 2-3 minutes, or until golden brown. Remove to a clean baking dish or sheet pan that will be placed in the oven. Once all chicken has been fried, place the sheet pan in the oven for 12 minutes. The chicken will finish cooking in the oven.
Remove the chicken from the oven and top each piece with about 1/4 of a cup of prepared tomato sauce, a sprinkle of dried oregano, and pieces of Mozzarella cheese and grated Parmesan. Return to the oven to bake until hot and bubbly and the cheese has melted, about 5 more minutes.
Remove from the oven and allow to rest about 3 minutes before serving.
Notes
To freeze: Prepare Chicken Parmesan as directed, without adding cheese and baking the final 5 minutes. Allow to cool completely, cover tightly with aluminum foil and freeze. To reheat: Remove from freezer and place in the refrigerator to thaw overnight or for at least 6 hours. Preheat oven to 450º F and top chicken with cheeses. Place in oven for 15 minutes to heat throughout and melt cheese.