Brown ground chuck and add taco seasoning and water according to package directions. Set aside.
In a separate bowl, combine sour cream, mayonnaise, 4 ounces of cheddar cheese and half of the onion, set aside.
Stir Bisquick mix and milk to form dough.
Press into a greased 9 x 13 greased baking dish on the bottom and up the side of the pan.
Saute remaining onions and green peppers until soft.
On top of Bisquick mix layer as follows: ground beef, tomatoes, green peppers and onion mix, jalapeno peppers, spread sour cream mixture evenly over the top, (like frosting a cake), top with remaining cheddar cheese.
Bake for 30-40 minutes or until edges of dough are lightly browned.