Leek and Potato Soup

We have a respite from the rain, so be sure to come to the Fairmount Neighborhood Farmers Market tomorrow and pick up some fall produce from Camas Swale Farm.

We are well into soup season now, and I wanted to share the recipe for my children's favorite soup, leek and potato, which I suspect they like because it's the closet one can come to eating mashed potatoes in liquid form. 

Leek and potato soup was also a favorite in my household growing up, and the soup my mother usually served on Christmas Eve along with smoked fish, a tradition my sister and I have continued. Along the way, we've tinkered with the recipe, and settled on two key steps to bring out the most flavor in this soup. The first (my sister's insight) is to create a soup base of leeks stewed for an extended period of time in butter and olive oil until they are a soft puddle of mush. This will take a good half hour and feel interminable, but it imparts a rich, sweet, leek flavor on the soup. The second (my addition) is to make a leek stock with the leek and potato trimmings (and if you had the foresight, a chicken backbone that you've stashed in your freezer), thus eking out every last bit of leek flavor from your ingredients. And of course, it doesn't hurt to finish the soup off with a generous glug of heavy cream.

Leek and Potato Soup

serves 4-6

6 large potatoes
2 large or 3 small leeks
2 Tbsp butter
2 Tbsp olive oil
1 cup cream
salt and pepper to taste
chives for garnish (optional)

1. Start the stock. Start heating about 8 cups of water in a stockpot with 1 Tbsp kosher salt. Cut off the green parts of the leeks. Rinse well, and chop coarsely, and add to the stockpot.  Rinse the potatoes, peel them, and submerge them in bowl with water to prevent them from discoloring. Add the peels to the stockpot. If you happen to have some other stock fixings (root vegetables, chicken backbone, an onion) add them to the stockpot as well. Bring to a simmer and cook for at least half an hour but longer is better. When to are ready to use the stock, pour to stockpot contents through a strainer into a large bowl or second pot and discard the solids. Taste for salt and add more as needed.

2. Prepare the soup base. Halve the white leek stocks lengthwise, rinse well and shake dry, and cut into 1/2 inch slices. Heat a large soup pot over medium low heat. Add the butter and olive oil, and once the butter is melted, add the leek slices and a pinch of salt. Turn the heat to medium low and cook the leek pieces, stirring often and avoiding letting them brown, until they are cooked through to a softened mound. This will take about 30 minutes, but is the secret to making the final soup very flavorful. 

3. Meanwhile, cut the peeled potatoes into 6 to 8 pieces. When the leeks are cooked through, add 6 cups of stock and the potato pieces. Bring the stock to a simmer and cook for about 30 minutes until the potato pieces are very soft. Remove from the heat and use an immersion blender to puree the soup until smooth. Add the cream. Taste and add more salt and pepper to taste. If the soup seems too thick, thin it with a little more stock. Return to the heat to warm to just below a simmer. Serve hot with chopped chives for garnish.