Cheese sauce without flour?
If you have evaporated milk (also known as unsweetened condensed milk) in your pantry, you can use it to replace everything except the cheese in a cheese sauce for stovetop macaroni and cheese.

Stovetop Mac and Cheese with Evaporated Milk Cheese Sauce

This recipe is an example of mac and cheese made with an evaporated milk cheese sauce.

Ingredients


  
  6 ounces (170g) elbow macaroni
  6 ounces (180ml) evaporated milk
  6 ounces (170g) grated mild or medium cheddar cheese, or any good melting cheese, such as Fontina, Gruyère, or Jack
  


Directions:


  
  Place macaroni in a medium saucepan or skillet and add just enough cold water to cover. Add a pinch of salt and bring to a boil over high heat, stirring frequently. Continue to cook, stirring, until water has been almost completely absorbed and macaroni is just shy of al dente, about 6 minutes.
  Immediately add evaporated milk and bring to a boil. Add cheese. Reduce heat to low and cook, stirring continuously, until cheese is melted and liquid has reduced to a creamy sauce, about 2 minutes longer. Season to taste with more salt and serve immediately.
  


The recipe does not drain the macaroni, but instead uses the remaining cooking liquid as part of the sauce. This is important, as the starch released by the pasta during cooking is needed to keep the sauce smooth.

(Consider this cheese sauce recipe, which uses a similar ratio of cheese to evaporated milk but also includes cornstarch. The "Read more" link in the recipe notes that a sauce made with just cheese and evaporated milk was significantly less smooth than a sauce made with both evaporated milk and cornstarch.)

A note for baked macaroni and cheese:

A footnote in a recipe for baked mac and cheese from the same website noted that a different cheese sauce recipe using evaporated milk did not work well in baked mac and cheese.


  I found that [the cheese sauce] didn't translate as well to the baked version of the dish; it tends to break when subsequently baked, diminishing its gooey texture and cheesy flavor.