Dice yellow onion, mince garlic, peel and grate the potato. Add to the meat and mix. Beat an egg and mix separately, then add to the meat as well. Finally, add the flour, seasoned salt and pepper, then mix everything thoroughly.
Shape the mixture into patties. (You should have about 15-16.) Pour some flour onto a plate and leave aside. Heat oven to 425°F.
Meanwhile, heat up oil in a pan on high. Dip each patty in the flour on both sides, and place each into the hot oil. Fry each side for about 2-2.5 minutes. (This is so they develop a thicker skin on the outside, and keep the juices in.) After you take each patty out, place them into a pan in which you'll be baking them. (The pan I used was about 12 inches in diameter.)
Bring the stove temperature to low, and then add butter to the oil in which the patties were fried. When the butter melts, start adding the flour in carefully, all the while mixing it in with the butter vigorously. You want to achieve a smooth sauce without flour crumbs in it. After flour and butter are combined together, add the heavy cream in very slowly while mixing the sauce all the while to avoid crumbling. Add the milk in while continuing to mix everything together. Finally, add the cheese in and continue stirring. Once it starts to boil (about 3-3.5 minutes) turn the heat off, and add the seasonings in.
Pour the sauce over patties, and place pan in the oven and cover with foil. After 30 minutes, turn the pan around. Bake for another 15 minutes without foil.
Serve with rice, polenta or mashed potatoes.