Baked macaroni and cheese is a classic comfort food. The rich, cheesy goodness is a favorite side dish at holiday and special occasion dinners. A large pan of macaroni and cheese serves a large group of people, but getting the texture just right can be an issue. Baked recipes often use a white sauce, also called a béchamel, in which the cheese is melted into and then mixed with the pasta. If you don't have milk or do not like milk, chicken broth is a viable alternative; just be aware that it will change the taste and texture of the finished dish just a bit.
The béchamel sauce used to make macaroni and cheese is traditionally made by melting butter in a saucepan and then stirring in flour. The flour cooks for about a minute to eliminate the starchy flavor and then milk is added slowly while whisking to produce a thick, white sauce. It is possible to replace the milk entirely with chicken stock in equal amounts. When this is done, it is no longer called a béchamel sauce, but a veloute. Mix the cheese into the veloute and allow it to melt thoroughly while stirring continuously.
When substituting chicken broth for milk in macaroni and cheese, it's important to be aware that the taste and texture will differ somewhat. Milk adds creaminess to the sauce that chicken broth just cannot replicate. The color and appearance of the sauce will differ as well. Instead of being very opaque, it will remain a bit translucent, similar to that of gravy. If the seasonings are kept the same, the actual taste remains very similar, but without the mouth feel of the extra creamy macaroni and cheese that many are accustomed to eating.
When making macaroni and cheese with chicken stock, make sure that your sauce is not watery or it will not bake properly in the oven. Use the same measurement of broth as you would have used milk. Once you mix the sauce together, it should still be thick. When stirring the sauce, there should be resistance on the spoon, as if you were stirring thick gravy. If the sauce is too thin, mix one tablespoon of cornstarch with just enough water to dissolve the cornstarch so it doesn't clump. Whisk this mixture into the sauce to thicken it up.
Since the taste and texture of the dish will change due to the substitution, consider making a trial run before making the recipe for a holiday dinner or other special occasion. You may find that you want to tweak the recipe by changing the spices or by using different kinds of cheese to make up for the difference. Spicing the dish using cayenne pepper or using different cheese such as smoked Gouda may help disguise the fact that milk was eliminated from the sauce. The final taste, though, is completely dependent on your own preferences. Making substitutions is often a matter of trial and error because not everyone likes the same thing.