Step 1: Prepare the Chorizo

1. Cook the Chorizo: Heat a cast iron skillet over medium heat. Add the chorizo and cook, breaking it into small pieces, until browned and cooked through, about 5-7 minutes. Remove the chorizo with a slotted spoon and set aside. Leave about 1 tablespoon of rendered fat in the skillet for added flavor.

Step 2: Make the Queso Fundido

1. Prepare the Roux: In a small saucepan, melt the butter over medium heat. Whisk in the flour and cook for 1-2 minutes until lightly golden.
2. Add the Milk: Slowly pour in the milk, whisking constantly to avoid lumps. Cook for 3-4 minutes, or until the mixture thickens.
3. Melt the Cheese: Reduce the heat to low and stir in the Pepper Jack cheese, smoked paprika, chili powder, and a pinch of salt. Stir until smooth and creamy. Remove from heat and set aside.

Step 3: Assemble the Nachos

1. Layer the Chips: Preheat your oven to 375°F (190°C). In the same cast iron skillet used for the chorizo, arrange a layer of tortilla chips.
2. Add Toppings: Sprinkle a portion of the shredded Oaxaca and cheddar cheeses over the chips. Spoon some of the cooked chorizo on top. Repeat the layers until all the chips, cheese, and chorizo are used, ensuring even distribution.

Step 4: Bake the Nachos

1. Place the skillet in the preheated oven and bake for 8-10 minutes, or until the cheese is fully melted and bubbling.

Step 5: Add Queso Fundido and Toppings

1. Drizzle the Queso Fundido: Remove the skillet from the oven and drizzle the warm queso fundido over the nachos.
2. Top It Off: Add your desired toppings, such as red onion, cilantro, pico de gallo, jalapeños, sour cream, and avocado.

Step 6: Serve and Enjoy

1. Garnish with lime wedges and serve the nachos directly in the skillet for a rustic, shareable presentation.