In a large mixing bowl, add the beef, 1/4 can of the mushroom soup, bread crumbs, egg, onion, and steak seasoning. Combine thoroughly, divide the mixture into 4 parts, then form each part into an oval.
In a large non stick pan, heat the oil and 1 tablespoon of butter. Add the patties and brown on each side then remove to a plate.
Remove the pan away from the heat and add the remaining butter and cognac (or wine), then return the pan to heat, when hot, saute the mushrooms until browned, then stir in the stock and gravy mix, then stir in the remaining mushroom soup. Add the patties to the pan and spoon the gravy over them, cover the pan and simmer for 20 to 25 minutes to thicken the gravy and finish cooking the patties through.
Serve with mashed potatoes, pasta, or even rice.