Heat oil in the pan and cook onions and garlic for five minutes. Keep it aside.

Mix ground beef, cooked onion, garlic, egg, tomato sauce, yellow mustard, and Worcestershire sauce in the bowl. Make four to five Salisbury steaks.

Heat cooking oil in the pan. Brown steaks in batches for two minutes. Keep steaks aside.

Saute mushrooms in the same pan for five minutes.

Heat oil in the pan. Add beef broth, mushrooms, onion powder, garlic powder, salt, black pepper, and Worcestershire sauce. Mix it well and stir in the cornstarch slurry. Transfer steaks to the gravy, cover, and cook for fifteen minutes.

Salisbury steaks are ready.