Preheat oven to 350 F and place your oven rack in the center. Spray a 13x9 glass baking dish.
Place biscuits in pan in a single layer and press into the pen, joining them together, pressing the dough halfway up the sides of the pan. Place pan on a baking sheet and bake dough in preheated oven for 15-25 minutes; checking every few minutes after 15. The dough should be very light brown where the edges are just starting to get color. Remove from oven and set aside, leave oven on.
While biscuits are baking, combine the browned ground beef with the taco seasoning and water, and cook according to packet instructions. Transfer cooked taco meat to a bowl and set aside. Wipe out pan.
In a separate bowl, combine sour cream, mayonnaise, half of the cheddar cheese, and half of onions. Stir well and set aside.
Saute remaining onions and bell peppers on the taco meat pan until slightly tender.
On top of baked biscuit crust, layer ingredients in the following order: taco meat, tomato slices, bell pepper and onion mixture, Jalapeno peppers, sour cream mixture and sprinkle with remaining shredded cheese. Bake uncovered for 30-40 minutes or until edges of dough are lightly browned and cheese is melted.
I highly recommend an oven thermometer. Your oven can actually bake hotter than what your knob is set at.