In a medium bowl, combine 3 cups of chopped brisket, 1 can of drained pinto beans, and ½ to 1 cup of BBQ sauce. Stir until everything is evenly coated in the sauce.

Preheat your oven to 350°F (175°C). On a large cookie sheet, spread a layer of lightly seasoned tortilla chips to form a solid base. Sprinkle half of the 4 cups of shredded Colby Jack cheese over the chips, then evenly distribute half of the brisket-bean mixture on top.

Add another layer of tortilla chips over the first layer, followed by the remaining brisket-bean mixture. Top this layer with the rest of the cheese.

Carefully place the loaded cookie sheet in your preheated oven on the middle rack. Set the oven to broil and let the nachos bake for about 2 minutes, or until the cheese is bubbling and golden brown.

Once the cheese is melted and the nachos are beautifully golden, remove them from the oven. Immediately sprinkle chopped cilantro, diced red onion, and sliced jalapeno on top.