In a large bowl, mix together all the ingredients for the steaks (except the oil) until combined.
Shape the mixture into 4 equal oval patties, about 3/4-inch thick.
In a large nonstick skillet, warm the olive oil over medium-high heat; add the steaks and cook, about 3 minutes per side until they get a nice golden crust (reducing the heat if they're browning too much.) Transfer to a plate.
Reduce the heat to medium and in the same skillet with the drippings, add butter. Once melted, add in the flour and whisk until combined and no lumps remain.
Reduce heat to medium-low and pour in the beef stock, whisking well. Add in the ketchup, Worcestershire, onion powder, whisking to combine.
Add in the mushrooms, then simmer for about 5 minutes to thicken. Season with salt and pepper, to taste.
Add the partially cooked steaks back to the skillet and nestle into the gravy; cover and cook another 10 minutes until cooked through (with an internal temperature of 160 degrees F.)
Serve steaks over mashed potatoes with some of the mushroom gravy drizzled on top.
For recipe variations, please refer to the full article.
To Freeze Uncooked Steaks - place the steaks on a lined baking sheet in a single layer, then flash freeze for about 2 hours until solid. Transfer them to freezer-safe bags or containers for up to 2 months. Thaw overnight in the refrigerator and proceed with the recipe as written.
To Freeze Cooked Steaks - allow to cool completely, then freeze steaks in the gravy in freezer-safe containers for up to 2 months. Thaw overnight in the refrigerator, then reheat in a pan or in the oven until warmed all the way through.
Nutritional information given is an automatic calculation and can vary based on the exact products you use and any changes you make to the recipe. If these numbers are very important to you, I would recommend calculating them yourself.