Impossible Cheeseburger Pie

Heat oven to 400 degrees.
Grease a 9 inch pie plate.
Sauté in butter or oil:
1 C. chopped onion
Add & brown then spread in pie plate:
1 pound ground beef
½ t. salt
Sprinkle with:
1 C. shredded cheese
Combine & pour on top of meat/cheese mixture::
½ C. Bisquick
1 C. milk
2 eggs
Bake 25 minutes or until knife inserted in center comes out clean.