Methods are key here, amounts less so. I mean, it's soup. Just wing it a bit, how bad will it turn out? I like my leek and potato soup pureed, because yum. But if you want it chunky, skip the pureeing part at the end and just smash it up some more.
So Ingredients:
- Start off with some leeks, or one leek plus a few onions and/or shallots. Leeks make for a milder soup and are more traditional, but an onion isn't going to hurt anything. If you don't have enough leeks, fill in with onions, they're cheaper.
- Then potatoes. Russets are stellar here, but white or red potatoes work fine, as do yukon golds. In my experience you just need to cook the white/red/yukon golds a bit more as they don't break down quite as easily as the russets. Maybe one or two pounds of potatoes for 4-6 quart soup? I like a potatoey soup though.
- Liquids. Stock (chicken or veg) is great if you have it, which most folks don't. Water plus a few boullion cubes is my go-to. I use a mix of chicken and veg, depending on what I have on hand. A bit of white wine or dry vermouth comes in handy. Your traditional vichyssoise is generally made with water, so it's not a problem if that's all you have.
- Garnish. I like dairy, cream, half and half, milk, full fat yogurt, sour cream--they all work on the individual serving level. I rarely add any to the big pot. Got something green? Chives or basil or something like that? Fine chop a bit.
- Fat. Butter, duh. Also olive oil, or a mix of the two. But come on, BUTTER. Also, if you're not vegetarian, bacon! Chop some up relatively fine, but not fussily so.
- Salt and pepper. I mean, what are you, a heathen?
So how do you make it?
Cut your aromatics. If you're using onions or shallots, peel and slice them relatively thinly. Start with the leeks: Take a thin slice off the root end of your leeks, and trim some of the tough green parts away from the opposite end. Then, take your knife and slice lengthwise down the leek shaft, to make two half-cylinders. Give both sliced lengths a good rinse in running water to get most of the grit out. Then slice relatively thinly into half moons. Dump those half moons into a bowl and cover with water. Swish around for a bit to let the remaining grit sink to the bottom. The half moons will float.
Grab a pot that holds about as much soup as you want to make. (I warned you it was a loose thing.) For me, I'll probably do a 4 qt pot with a few pounds of potatoes, 2 smallish leeks and an onion or two. Any more than that and I'd bust out the dutch oven instead.
If you're using bacon, chop it fine-ish, and cook on med high heat until the fat renders out. Otherwise, melt in a chunk of butter and a swirl of olive oil--about 2 tbsp butter at least? Once the foam has subsided, throw in the sliced onion and/or shallot if using. Using your hands, lift the leek half moons out of the water, and throw them in as well. Don't drain with a colander unless you want to dump your grit back over your veg or pick little itty bitty slices of leek out of the holes. Give the leeks/onions/shallots a big ass pinch of kosher salt--nearly 1/2 a teaspoon please--and a hearty stir. Lower the heat to med-low and let cook until translucent, stiffing occasionally, and maybe slightly starting to turn color.
Traditionally you're not supposed to let your aromatics color for this kind of soup. But for me? Color equals flavor so I let 'em brown a bit, depending on how impatient I am and how closely I've been paying attention to the pot.
While they're cooking, peel and cube your potatoes. You don't need to be neat about the cubes, but smaller pieces cook faster. So keep that in mind.
Are your aromatics aromatic and soft? Good. Crank the heat a bit, and throw in a glug of white wine or dry vermouth, and give a stir. Let it bubble and reduce a bit. Think you want some more of it? Throw in some more. Just let it bubble and reduce and you'll be fine.
Next, put in your cubed potatoes. Then add your stock or water to hit just about the level of soup you want to make. Pro tip: don't do what I do nearly every time and add the water then the potatoes, and nearly have overflowing soup. Throw in your bouillon cubes--I use maybe 6 for a 4 quart pot? And add a bit more salt. Even with bouillon cubes, you've got potatoes in there. They NEED salt.
Bring to a low boil, then reduce heat so it is simmering (more for overflow purposes than for burning things). Cook until the potatoes are falling apart tender, anywhere from 15 to 30 min. I mean, it's soup, you're not going to overcook the damn things.
Remove from the heat and puree. I use a stick blender (affiliate link) because holy crap is that thing awesome and easy to use. Whizz the soup up, and done. You can also pour a bit of the soup into a regular blender whizz that, then do some more, etc etc. Or just spend the $35 at Bed Bath and Beyond and get a stick blender and never look back.
Taste for seasoning, add salt and pepper as needed. Serve.
I like mine topped with a plop of sour cream or yogurt and then some chives. Or some basil oil (whizz olive oil with basil leaves with your stick blender). Or a glug of half and half and a ton of pepper. Or some crispy fried shallot rings (or French's deep fried onion rings from the can, don't be proud, those things kick ass). Oh, and buttered toast. Yum.
The soup keeps well in the fridge, and will pretty much gel into a potato-y sludge when cool, because hi potato starch. It loosens as it heats up though. It tends to separate when frozen, which means when you defrost it you need to stir the shit out of it. And don't freeze if you've added dairy to the whole batch. It get nasty.