Place the ground beef, salt, garlic powder, black pepper, ketchup, Worcestershire sauce, steak sauce, egg and breadcrumbs in a large bowl. Mix the ground beef with your hands until all of the ingredients are incorporated.

Add enough oil to a large, deep skillet to cover the bottom by ¼ - ½ inch (about 1½ cups).

Heat the oil over medium-high, until hot but not smoking. Add the meatballs. Make sure to leave some space in between so they’re not touching and so that you can turn them. Cook in batches if needed.

Cook the meatballs about 5 minutes or until they’re browned on all sides. Turn them every two minutes or so.

Remove the skillet from the heat and remove the meatballs, set them on a plate or pan. Cover loosely with a piece of foil and/or place in the microwave or oven to keep warm. Don’t worry that they are not cooked all the way through. They will finish cooking in the gravy.

Drain the excess grease, but do not wash or wipe the skillet.

Place the skillet back over medium heat and add the butter. When the butter is melted and foamy add the onions. Cook them gently for 3-4 minutes until they start to soften, stirring frequently.

Next, add the mushrooms. Cook them gently for 3-4 minutes until they become golden-brown in spots, stirring frequently.

Add the flour to the onions and mushrooms, stir to combine and cook for 1-2 minutes, stirring frequently.

Raise the heat to medium-high and add the beef broth, while stirring and gently scrapping any bits off the bottom of the skillet. When the sauce comes to a simmer add the meatballs back to the pan.

Let the sauce come back up to a simmer. Lower the heat to medium low, cover and cook the meatballs for 15-20 minutes, stirring occasionally and turning the meatballs. Keep at a simmer, raise or lower the heat a bit, as needed.

Taste the gravy and add salt, if needed. As a reference, we did not add extra salt to ours.