Potato Potage

Yield:	4 Servings
Categories:	Soups, Potatoes

1/2	c	Celery; sliced
1/4	c	Onion; chopped
2	tb	Margarine
1		8 oz package cream cheese; cubed
1	c	Milk
2	c	Potato; chopped and cooked
1/2	c	Water
2	tb	Parmesan cheese; Grated
1/2	ts	Dry mustard
1/2	ts	Salt
	ds	Pepper