Bavarian Potato Salad

I remember enjoying the potato salad in Germany, but not finding anything like it in recipe books. Then I found one in the newspaper and modified to my taste.

	5 lbs potatoes, peeled & sliced
	2 red onions, diced large
	1/4 cup vinegar (I use malt vinegar)
	1 Tbl butter
	2 Tbl Dijon mustard
	2 Tbl mayonaise
	2 tsp salt

	Bring enough water to cover the potatoes to a boil.  Add
	the potatoes and cook for 5 to 7 minutes, then cool.  Saute
	onions in butter for 5 minutes, then cool.  When potatoes
	and onions are cooled, mix all ingredients together.