1 lb. hamburger
1 1/2 c. milk
3 eggs
1 1/2 c. chopped onion
3/4 c. Bisquick baking mix
1/2 tsp. salt
1/4 tsp. pepper
1 c. shredded Cheddar or American cheese

Heat oven to 400 degrees. Grease pie plate. Cook and stir beef and onion over medium heat until beef is browned. Drain, spread in plate. Beat milk, baking mix, eggs, salt and pepper until smooth, 15 seconds in blender on high, or 1 minute with hand beater.

Pour into pie plate. Bake 25 minutes. Top with tomatoes, if desired. Sprinkle with cheese. Bake until knife inserted in center comes out clean, 5 to 8 minutes. Cool 5 minutes.