1 lb. ground beef
1/2 c. onion, chopped
1 envelope taco seasoning mix
1 1/4 c. milk
3/4 c. Bisquick mix
3 eggs
1 c. Cheddar or Monterey Jack cheese, shredded

Heat oven to 400 degrees. Grease a 10 x 1 1/2 inch pan. Cook beef and onion until brown, drain. Stir in seasoning mix. Spread this into pan. Beat milk, baking mix and eggs until smooth, (15 seconds in blender or 1 minute with mixer). Pour on top of meat mixture in pan. Bake 8 to 10 minutes or until knife inserted comes out clean. Cool 5 minutes. Top with sour cream, tomatoes, lettuce and cheese, if desired.