Impossible Cheeseburger Pie

Cook up:
1 lb. hamburger
1 1/2 c chopped onion

Mix until smooth:
1 1/2 c. milk
3/4 c. Bisquick
3 eggs

Layer in pie pan:
bottom layer hamburger mixture
top layer is milk and eggs mixture

Bake at 400 for 25 minutes.
Top with 2 sliced tomatoes and
1 cup shredded cheddar or american cheese
Bake an additional 5 to 8 minutes.

Variations I made:
I do not use onion or tomatoes
Substituted handful of mozarella cheese.
Mixed everything together: beef, milk, eggs, cheese, bisquick
Did not add anything to the top since cheese inside

From Bisquick recipe book circa 1982