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, oregano, salt, and pepper together in a second shallow dish. Dip tenderloins in egg mixture, then in bread crumb mixture until well coated.

Heat oil in a large skillet over medium-high heat. Working in batches as necessary, fry breaded tenderloins in the hot skillet and until golden brown on both sides, 2 to 3 minutes per side; they will not be cooked through. 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 into the baking dish with browned tenderloins. Cover the dish tightly.

Bake in the preheated oven until no longer pink in the center, about 45 minutes. An instant-read thermometer inserted into the center should read at least 145 degrees F (63 degrees C).