Alright, it's that time of year when it's blistering cold; and the best thing to warm you up is a hot bowl of hearty soup. Seriously, between this soup and beef stew; there's no need for central heat. Talk about comfort foods - gah.
Boil and mash three or four large 'baking potatoes' (Russett's). Dice two more (or three red potatoes) and leave raw. I use red potatoes in this second part becuase they give the soup more body. But whatever.
Sweat three leaks (sliced, white stalks only), a medium yellow onion, and a couple cloves are garlic until soft; not translucent. Add a couple teaspoons of thyme.
Add a quart or two of milk to the sweat, salt and pepper to taste, and bring to a bare simmer.
Toss in both the mashed and diced potatoes, maintaining a bare simmer. Salt and pepper to taste again, as this drastically changes the volume of the soup. Cook until the diced potatoes are soft enough to your liking. Check the spicing again, and when you're satisfied; remove from heat and stir in a cup or two of heavy cream. Garnish with parsley.
A note about the milk/cream: That's just a guideline. I was making this recipe one night and realized all I had was less than half a gallon of milk and a 1qt container of half-and-half. I couldn't leave the house, and using two quarts of milk was impossible. Instead I used: maybe two cups of milk, a cup or two of chicken broth, a cup or two of water; and instead of cream at the end I used a cup and a half of half-and-half. When I mashed the potatoes I mashed them up with maybe a tablespoon of lard just to make sure I got some of the fat back into the soup.
Regardless, the consistency should be not as thick as mashed taters, but not as thin as chicken noodle soup. Think thick chowder or something.