Impossible Cheeseburger Pie

1 pound ground beef
1 cup chopped onion
1/2 teaspoon salt
1 cup shredded Cheddar cheese
1 cup milk
1/2 cup Bisquick
2 eggs

Heat oven to 400 degrees F.

Cook ground beef and onion; drain. Stir in salt. Spread in a greased 9-inch pie plate; sprinkle with cheese. Stir remaining ingredients with fork until blended. Pour over meat mixture. Bake 25 minutes or until knife inserted in center comes out clean.