Preheat the oven to 375 degrees F. Start by making the enchilada sauce below. Spray a 9×13 inch baking dish with nonstick spray. Take about 1/2 cup of enchilada sauce and spread it on the bottom of the dish. Take a large plate and add 1/3 cup of enchilada sauce on it.
Take each tortilla and dip it into the enchilada sauce on the plate. Fill it with a handful of the cheeses (I mix mine together). Roll up the tortilla and place it in the dish – I like to do two rolls of 6 or 7. Repeat with remaining tortillas. Cover the tortillas with the sauce that is left and then sprinkle with the remaining cheese. Bake for 20 minutes, or until the cheese is bubbly and melty. Serve immediately with your desired toppings.
Heat a large saucepan over medium heat and add the olive oil. Whisk in the flour and cook until it is golden brown, about 2 minutes. Add the remaining ingredients and whisk together, bringing the mixture to a simmer. Reduce the heat to low and cook for 5 more minutes before using.