Cream of Potato-Bacon or Potato-Leek Soup

An onion or two, finely diced, sweated and then cooked in a couple of tbsp of butter (NOT margerine) until clear. Put aside to add later.
A bunch of potatoes (russets are good) peeled or not - it's healthier with the skins, but not as pretty - and chopped. Boil until mostly soft.
Strain the potatoes, then add the onions/butter and a few cups of stock (I prefer chicken or duck stock, but just about any kind except beef, veal or lamb is good).
Seasoning: I love to use fresh dill, but if that's not available dry is fine, as well as lots of pepper (white pepper if you've peeled the potatoes), salt, and maybe a little basil and/or oregano.
After it's all really well cooked, use a hand emulsifier to puree the whole thing until smooth (or do it in batches in a food processor), adding cream (1-3 cups, depending on how big of a batch you're making) as you blend.

Variations: for potato-leek soup, add a full head of leeks (washed and chopped finely) when you add the onions and stock. For potato-bacon soup, fry 1/4 - 1/2 lb bacon until fully cooked but still fairly soft (not crispy!), chop finely, and add either right before or right after pureeing, depending on how chunky you want it.