Preheat the oven to 325°, and place the oven rack on the middle rack.

Spray a 9x13 baking dish with nonstick cooking spray.

Brown ground beef in a large skillet until no longer pink, add the packet of taco seasoning and ½ cup water, simmer for 2 minutes.

Remove the meat from the skillet and sauté the onions and bell peppers for 4 minutes.

In a medium bowl combine mayonnaise, sour cream and ¾ cup cheese.

In a separate bowl combine the bisquick mix and remaining water. Make a biscuit dough and press into the bottom of the baking dish, press it up the sides of the dish about a half inch high on all sides.

Spread the ground beef evenly over the dough.

Next, add the bell peppers and onions. Then, spread the sour cream mixture evenly across the top.

Now, layer sliced tomatoes and pepperoncinis. Then, add the remaining cheese.

Place on the middle rack in the oven and bake for 30-35 minutes.