In a cast iron skillet, caramelize the onions and mushrooms with butter and salt on low to medium heat. Set aside.
Cut round steak into personal size pieces.
Combine flour and salt in a flat dish, like a glass baking dish.
Pound round steaks on both sides to help tenderize them.
Dredge meat on both sides in flour. I find using either tongs or one hand to dip is easiest (and cleanest).
Place round steaks into a hot pan and fry them one or two minutes on each side to brown them. Place in a Dutch oven.
Add caramelized onions and mushrooms, and a tablespoon of flour from the dredging bowl to the skillet to make a gravy from the drippings. Use a spatula to scrape up some of the bits from the bottom of the skillet.
Pour gravy and onions over round steak, as well as any fresh herbs (I used a large handful of fresh rosemary from the garden), cover with lid, and place into preheated 350 degree Fahrenheit oven for 2 hours.
Notes
Make sure to tenderize both sides of the meat.
Caramelizing onions takes patience. Low and slow is the best way to get the onions to caramelize without burning.
Getting a good browning on the meat adds flavor and helps lock in the juices. Don’t skip this step.
Allow to cool completely before storing. Store in an airtight container (I prefer glass) for up to 4 days.
Reheat in a cast iron skillet on medium low heat until heated through.