Dredge 2-3 cube steaks (both sides) in flour seasoned with fresh cracked pepper.
Heat the olive oil in an ovenable, stock pot on top of the stove.
Brown each side of the cube steaks in the heated oil. Then remove them from the stock pot onto a plate to rest temporarily.
Dice the onion and toss into the stock pot with the remaining pan drippings etc.. Cook and stir until the onions are translucent.
Next, add the dry packet of brown gravy mix into the stock pot with the onions and pan drippings. Add 1 cup of water stirring constantly over the heat until an onion gravy is made and bubbling.
Then, add the can of drained, sliced, button mushrooms and toss lightly in the onion gravy mixture. Turn off the heat.
At this point, add the cube steaks back to the stock pot mixture, laying them on top of the gravy. Then, generously spoon gravy on top of the cube steaks to cover them as well.
Put a lid on the stock pot and place it into a preheated 350° oven and bake the cube steaks for 45 minutes.