Preheat your oven to 400°F and line a large sheet pan with aluminum foil or parchment paper. Lightly grease the foil or paper with cooking spray to prevent sticking.

Arrange the tortilla chips in a single layer on the prepared sheet pan, ensuring there are no gaps.

If you're using ground meat, cook it in a skillet over medium heat until browned and fully cooked through. Drain any excess fat and season it with your preferred taco seasoning. Set aside.

In a medium saucepan over medium heat, melt the butter for the cheesy sauce. Once melted, add the flour and whisk continuously for 1-2 minutes to create a roux. It should become a light golden color.

Gradually pour in the milk while continuing to whisk, ensuring there are no lumps. Cook for about 2-3 minutes until the mixture thickens.

Reduce the heat to low, then stir in the shredded cheddar cheese, garlic powder, onion powder, salt, and black pepper. Keep stirring until the cheese is completely melted and the sauce is smooth.

Pour the cheesy sauce evenly over the tortilla chips on the sheet pan.

Scatter the black beans, diced tomatoes, sliced black olives, pickled jalapeño slices, and diced red onion evenly over the nachos.

Add the cooked ground meat (if using), then sprinkle the shredded medium cheddar cheese and Monterey Jack cheese over the nachos.

Place the sheet pan in the preheated oven and bake for about 5-10 minutes, or until the cheese is melted and bubbly, and the nachos are heated through.

Remove the sheet pan from the oven, and let it cool for a minute or two. Drizzle sour cream and sprinkle fresh cilantro on top for a burst of freshness.

Serve the loaded cheesy sheet pan nachos directly from the pan, or transfer them to a large platter. Don't forget to have extra salsa, guacamole, and sour cream on hand for dipping!