Combine the first 4 ingredients in a small bowl to make the seasoning mix.
Place the meat on a flat surface and pound each steak with a meat mallet or the side of a saucer, turning the meat as you pound it, until about ¼ inch thick. Sprinkle ½ teaspoon of the seasoning mix on each side of each steak and rub it in well.
Combine ¾ cup of the flour with 1½ teaspoons of the seasoning mix in a shallow bowl. Whisk together the egg and milk in another shallow bowl, beating until very frothy and pale yellow.
Heat the oil in a heavy 12-inch skillet over high heat to 350°, about 5 minutes. While the oil is heating, dredge the steaks one at a time in the seasoned flour, then let them soak 1 to 2 minutes in the egg mixture. When the oil is hot, dredge each steak one at a time in the flour again, pressing the steak into the flour to coat it thoroughly, and immediately place it in the hot oil. Fry the steak until browned, about 2 to 3 minutes on each side. Remove it from the skillet, set aside and keep warm, and repeat the process with the other 3 steaks. You can fry more than 1 steak at a time, if you can keep track of which one needs to be turned or removed, and as long as you place each steak in the skillet directly after the second dredging in the flour.
Pour out and discard all but 1 tablespoon of the oil from the skillet in which the steaks were cooked, leaving the residue of juices from the meat and any brown crust remaining on the bottom. Heat over high heat, and when the oil sizzles, add the onions and cook until light golden brown, about 3 minutes. Stir in the remaining 3 tablespoons of flour and gradually add the stock, whisking constantly. Add the remaining seasoning mix and continue whisking until the gravy comes to a boil, about 2 minutes. Add the cream and parsley and cook 1 minute, whisking constantly. Serve immediately.