Recipe: Leftover Potato Soup

In addition to the usual charcoal ash and foggy head, another thing we were left with following this year's Memorial Day holiday was an excess of plain boiled red potatoes. Having exceed our quota of scrambled eggs and fried potatoes for the week with a large bowl of cold starch still in the refrigerator, we tried to think of other uses. This is what we did.

This is barely a recipe; it's more a prompt for experimentation and an encouragement to view leftovers as something more than just a slightly stale version of what you ate yesterday.

Leftover Potato Soup

This is little more than a standard, if not quite wholly traditional, potato leek soup or vichyssoise, depending on how French one wishes to sound.


We give only loose measures here—first, because making soup does not require the laboratorical care of, say, baking a cake, and second, because encouraging variation from what we produced this week is part of the point. (And, third, because we are reconstructing from memory several days after the fact now, anyway.)

Ingredients
4 leeks
1 quart chicken stock
2 pounds leftover boiled red potatoes
2 uncooked Russet potatoes
1 pint half and half
milk
dry white wine
butter
Kosher salt
black pepper
Cayenne pepper
Cognac
chives

Equipment
soup pot
immersion blender
two large bowls
knife and cutting board
kitchen shears

Method
Rinse leeks. Cut off and discard tips. Cut remaining white portion into slices. Discard green portion. Place slices into bowl of cold water, separating rings to the extent possible. Allow leeks to soak for several minutes at least to allow sand between layers of the leek to settle out.

Peel Russet potatoes and cut into small chunks. Place into dry bowl and cover with water. Discard starchy water immediately and cover with clean water. Allow potatoes to soak for several minutes at least to leech out excess starch.

Drain, rinse, and dry leeks. Melt several tablespoons of butter in pot over medium heat. Add leeks. Sweat leeks by cooking them until soft but not browned.

Drain raw potatoes. Add raw potatoes, cooked potatoes, chicken stock, a heavy splash of wine, salt, black pepper, and Cayenne pepper to pot. Liquid should nearly or entirely cover all solids. Add stock, wine, or water as needed if volume of liquid initially isn't sufficient. Turn up burner heat to medium high. Allow stock to simmer. Cover pot. Reduce heat to maintain simmer.

Allow the stock to simmer for 20 minutes or until the raw potatoes are cooked and soft throughout. Remove pot from heat and allow to cool for a minute or two. Blend mixture with immersion blender. Add half and half. Blend again. Alternately add small quantities of milk and blend the mixture until you've achieved your preferred consistency, remembering that the soup will be thicker when it's cold, should you intend to eat it that way. Add a splash of Cognac. Use nothing fancy. We generally use Salignac VS Cognac, about $17 per fifth at retail. Blend again.

Taste the soup again and add salt and the peppers as you desire. (We make explicit this tasting step as a reminder to do it once again near the end of the process, but if you're ever waiting for our permission to taste what you're cooking, you may want to reexamine your relationship to authority.)

If you intend to eat the soup hot, return it to the burner and heat it over low until hot throughout. Otherwise, allow the soup to cool, preferably in an ice bath, then refrigerate it until cold.

As you wait for the soup to reach the desired temperature, wash the chives. Three or four chives per serving is appropriate.

Once the soup has reached the desired temperature, ladle it into bowls, take a few chives, and cut the chives over the bowl using kitchen shears.

Serve.

Notes
The procedure above approximates what we did with our leftovers, including the addition of a few raw Russets. Do what suits your mood and available ingredients. Start with all cooked potatoes or all raw. Start with baked or roasted or mashed potatoes. Leave the skins on or take them off. Use exclusively heavy cream or exclusively milk. Swap sherry for Cognac and an ale for the wine. Add half a sweet onion to the leeks. Add mushrooms. Add bacon. Eat hot. Eat cold. Do whatever. Assuming the soup is salted correctly and you're happy with the consistency, it's next to impossible to screw this up.¹ And even if you do manage to end up with something horrible, at least, we hope, you've learned something for next time.

If you do try your own variation, please do let us know, either by leaving a comment below or by e-mailing us.

It was a busy evening at the B&B editorial office, and we were thankful to have a bit of this soup left in the refrigerator to anchor a late meal of soup and salad.



---
1. Do not, however, try to use a food processor in place of the immersion blender. Not only will end up with (literally) a hot mess, but whatever soup you manage to retain in the bowl of the machine will be turned into something resembling paste more than soup. If you haven't yet gotten around to spending the $15 at Target for an immersion blender, let the soup cool down a little more, then transfer it in batches to a standard bar blender and puree. Failing that, just force the whole thing through a drum sieve.