Let the Cube steak come to room temperature, which takes about 10 minutes
Heat a cast iron pan on the stove with the oil. Sear the steaks for 30 seconds to 1 minute on each side. Set the steaks aside and cook the onions and mushrooms until they are starting to soften and brown slightly
Preheat the oven to 300 degrees F
Move the steaks to a Dutch oven or lidded roasting pan. Sprinkle on the seasonings, patting them into the meat
Pour in the 2 cups of beef broth. Cook for 1 hour with the lid on. Remove from the oven and remove two cups of liquid from the pan. If there aren’t two full cups, add more broth to make up the difference
In a saucepan, melt the stick of butter and stir the flour in. Stir regularly as it cooks over low heat, moving it around to prevent scorching. When this mixture is a light nut brown color, pour in the 2 cups of liquid a little at a time. Keep stirring until the gravy is glossy and thick, mix in the thyme, then remove from heat
Cover the steaks with the thickened gravy, then cook for another 45 minutes
Serve with mashed potatoes or rice
