In a medium sauce pot, melt the butter and add the flour and whisk to combine. Cook the flour for 2 minutes and then whisk in milk. When the milk comes to a rolling boil, stir in the shredded cheese and stir to combine. Once smooth, remove the cheese sauce from the heat and set aside.

Preheat your oven to 350 degrees.

Place a layer of chips on a tin foil sheet. Layer with shredded cheese, cheese sauce and various toppings and transfer to the oven to let the cheese melt.

Once melted, carefully remove the nachos from the oven and top with any remaining ingredients like guacamole and pico de gallo. Serve immediately.