Preheat your oven to 350°F and lightly spray a 9x13-inch baking dish with nonstick cooking spray.
Place the biscuits in the dish in a single layer. Press them together so that they cover the bottom and reach about halfway up the sides. Bake for 15-20 minutes until the edges start turning light brown. Remove from the oven, but keep the oven on.
In a large skillet, cook the ground beef over medium heat until no pink remains. Drain off excess fat. Stir in the taco seasoning with the required water and simmer until the sauce thickens.
In a bowl, combine the sour cream, mayonnaise, and half of the cheddar cheese. Set aside.
Using the same skillet, sauté the sliced onions and bell peppers until they are just tender, about 3-5 minutes.
Spread the cooked ground beef over the baked biscuit base. Layer tomato slices evenly on top, then add the sautéed vegetables and canned jalapeño peppers. Drizzle the cream mixture evenly over the layers and sprinkle with the remaining cheddar cheese.
Bake the assembled casserole uncovered in the oven for 30-40 minutes until the cheese is melted and the biscuit edges are lightly browned.