Impossible Cheeseburger Pie
["1 pound extra-lean ground beef", "1 cup chopped onion", "1/2 teaspoon salt", "1 cup shredded fat-free cheddar cheese", "1/2 cup Bisquick Reduced Fat baking mix", "1 cup skim milk", "2 eggs"]
["Heat oven to 400\u00b0.", "Grease 9-inch pie plate.", "Cook ground beef and onion until beef is brown; drain.", "Stir in salt.", "Spread in pie plate; sprinkle with cheese."]
["extra-lean ground beef", "onion", "salt", "cheddar cheese", "Bisquick", "milk", "eggs"]