We had this a few nights ago. Or at least some version of it. Wife often modifies a recipe based on what she happens to have on hand. She is a good enough cook and has cooked long enough to pretty well know what substitutions will work and which will not. Failures are very rare.

Very delicious. She makes the white sauce for various dishes pretty often. It makes up for not having flour gravy. Will even use it sometimes on a meat pizza (meatza) but sometimes we still go tomato based.

https://www.youtube.com/watch?v=bQwQ_J4mBqw&t=6s