Trim the loin and cut it into four equal pieces. Butterfly each piece but slicing almost all the way through it. Open like a book, place on a cutting board, covered with a piece of plastic, if desired, and pound to a thin cutlet, about 6 to 7 inches in diameter, or more, up to 10 inches. It should be about 3/8ths of an inch thick when finished. It is best to use both the pointy and flat side of the mallet, and be careful, there should be no holes and the cutlet shouldn’t be too cut up when finished, it needs to hold together in one piece. Set aside.

Set up a breading station with three large, shallow plates. Place flour in the first, egg and milk in the second, and the breadcrumbs, salt & pepper and the cayenne in the third. Mix together the egg and milk and the breadcrumb and seasonings.

Add about 3/4 inch of oil to a skillet, cast iron works well and heat to 350 degrees F. Preheat oven to 250 degrees.

In the meantime, bread the cutlets, dipping first into the flour, pressing gently to make certain flour has thoroughly adhered. Shake off any excess. Dip next into the egg/milk mixture, letting any excess drip off. Lay the cutlet into the breadcrumbs and toss more bread crumbs on to the top. Press gently to make sure they adhere. Turn over and do the same to the other side. Gently pick up, trying to avoid bending the tenderloin so that fewer breadcrumbs are lost. Turn vertically to dump off any excess bread crumb and carefully place it into the hot oil.

Fry in the hot oil until golden brown, two to three minutes per side. Remove to a wire rack over a baking sheet and place in the warmed oven until all cutlets are cooked. Repeat with remaining cutlets, working in batches if necessary.

Serve on a bun with lettuce, pickle, and onion; mustard is the condiment of choice.

Note: if desired, other spices may be added to the breading. Onion powder and paprika are not uncommon.