Salisbury Steak with Mushroom Gravy

1 lb. lean ground beef                                  1 medium onion, quartered, then sliced

1 egg                                                          1 jar (4.5oz) sliced mushrooms, drained

½ cup Bisquick                                            1 can cream of mushroom soup

1/8 tsp. pepper                                            1 cup beef broth

1 Tbsp. vegetable oil

In a large bowl, mix beef, egg, bisquick and pepper.  Shape meat into patties about ½” thick.  In large nonstick skillet, heat oil over medium heat.  Arrange patties in single layer in skillet.  Add onion slices around and on top of patties.  Brown patties on both sides.  Remove patties and any fat from skillet.  Add broth to deglaze pan and stir in mushrooms and soup.  Get any brown bits off bottom of pan.  Add patties back in and coat with sauce.