To begin, sauté the sausage in a large skillet over medium high heat until it is cooked through and browned on the edges. While it cooks, use your spoon to break up the sausage into little bits and stir it continually.
Scoop the sausage from the skillet and place it on a plate that is lined with a paper towel.
Add the butter to the drippings that are still in the skillet. Melt it over medium heat.
Sprinkle in the flour and whisk them together. Then, let them cook together for one minute.
Pour in the evaporated milk and whisk together. Bring this up to a gentle simmer and cook for a minute – stirring continually.
Reduce the heat to low and add in the Neufchatel cheese and half of your shredded cheddar cheese. Stir until it is melted in. Do the same with the other half of the cheese.
Add in the diced tomatoes with green chilies.
Finally, add in most of your cooked chorizo and stir it all together. Reserve some of the chorizo to sprinkle on top as a garnish before serving.