This simple sauce is the base for many delicious things that we eat. Once you learn how to master it, the quality of your meals will be greatly elevated.
Bring your white stock to a simmer in a small sauce pot. Reduce heat and keep warm.
In a heavy bottomed sauce pot over medium heat, melt the butter. Add in the flour to create a roux and cook the roux for 1 Minute. Let sit 1 Minute.
Vigorously whisk in half of the stock until the sauce begins to thicken. Watch for clumps and whisk them out if you see any.
Add in the rest of the stock and bring it to a boil. About 10 Minutes.
Reduce the sauce to a simmer and cook for 1 Hour, or until the desired napé consistency* is reached and the sauce has reduced by about ⅓. Stir and skim the surface as needed.
Strain the sauce through a sieve lined with cheesecloth and store in the fridge up to 5 days. Do not season the sauce - it is intended to be used as a base, not an ingredient.
Notes
*A napé consistency is when the sauce coats the back of the spoon.