Cook in a medium sauce pan 2/3 full of water.
In a large sauce pan melt and brown 3/4 stick of butter. Want it browned but not burnt. Then add 1/8 cup of flour and brown a little...stirring with a whisk. Add 1/2 cup of milk stirring mixture with a whisk Add potato/celery/onion water mixture, continuing to stir with a whisk Add additional milk to make a good soup consistency...don't want it too thick heat on high until hot...not boiling! Turn to low.