potato leek soup
Julia Child's is utterly simple, easy, and delicious. Looks as if it's posted several places online: http://splendidtable.publicradio.org/.... I definitely recommend pureeing it w/ an immersion blender, and then serving w/ a dollop of sour cream or creme fraiche (and chives, watercress, etc. if you wan to be fancy).
IMO, a potato leek soup with nothing else but cream/milk, butter and S&P is the best, and really showcases the potato and leek flavors. I saute the leeks in butter until soft, then puree with peeled, cooked cubed potatoes and just enough milk to liquify it all. Reseve a couple pieces of uncooked leek and fry to a crisp for a garnish.