Step 1

In a saucepan, melt the butter over medium heat. While stirring, slowly add the flour to the butter. Keep stirring to ensure the butter fully incorporates and doesn’t form lumps. Keep adding the flour until the mixture creates a loose paste.

Step 2

Slowly pour the chicken stock into the saucepan with the roux, whisking continuously. Once added, the chicken stock should not have any lumps of roux in it. Bring the mixture to a simmer and let it reduce, frequently stirring, for 20-30 minutes. You can tell it’s done once the sauce coats the back of a spoon and is glossy and velvety in appearance.

Step 3

Pour the sauce through a fine-mesh sieve (or cheesecloth) into a bowl. The sauce will keep well in the refrigerator for up to three days, or you can freeze it for up to three months.