Preheat the oven to 325 degrees F (165 degrees C). Line a 9x13-inch baking dish with aluminum foil.

Slice tenderloin into 1/4-inch rounds. Pound each slice between sheets of plastic wrap until thin.

Whisk milk and eggs together in a shallow dish. Whisk bread crumbs, oregano, garlic salt, salt, and pepper together in another shallow dish. Dip tenderloins in the egg mixture, then in the bread crumb mixture until well coated.

Heat oil in a large skillet over medium-high heat. Fry breaded tenderloins in the skillet until golden brown on both sides, about 2 to 3 minutes per side. Transfer browned tenderloins to the prepared baking dish.

Mix any leftover egg and bread crumb mixture together, then fry it in the hot skillet. Place it into the baking dish with browned tenderloins. Cover the dish tightly with foil.