My sister Grace lives in Atlanta and is the new mother of my two scrumptious little nieces. After she traded in her flight attendant’s uniform for maternity jeans a couple of years ago and got a schedule that allows her to be at home for more than a couple of days at a time, she’s become a kitchen enthusiast, even started canning last summer. She texted me this after I posted the split pea soup last week:
“Glad you posted that soup recipe. I’m cooking again and it feels nice. I have two comments about the potato leek soup before I forget them.
1. We need proportions and 2. using an immersion blender turns it into paste.
How do you keep that from happening?”
A few months after I started this blog, I wrote a post about a neighbor in our community garden who gave me a bunch of leeks. I used them to make a simple potato leeks soup but didn’t really post a recipe, more of a general description of the process. Grace has been asking me to write down the actual recipe ever since I made it for her and her now-husband when they came out for a visit but I never got around to it. Now that she’s feeding it to her children, I figured it’s time to take my responsibility as an aunt seriously and finally get her the recipe.
The paste issue is another story. We have a family Christmas tradition that my mom started of making a pińata with newspaper and flour paste. Most starch can be turned into some kind of glue when it’s mixed with water and potatoes are no exception. Overworking potatoes, which is easy to do with any tool more powerful than your arm, turns them into paste. I’ve made mashed potatoes that you could mortar bricks with before I learned better.
So, the goal is to blend the soup enough so that it’s smooth but not so much that it becomes gluey. Julia Child recommends either beating the soup with a fork or using a food mill, but I like a smoother puree than a fork will get me and I know a lot of kitchens aren’t equipped with food mills, so I use a hand-held stick blender as my first choice; it’s the easiest tool to control. A blender or food processor will work, but be judicious and just do a few quick pulses until it is smooth.
Another way to minimize the amount of blending is to cut the vegetables into small pieces to begin with; they will soften a lot while they cook and melt into a smooth puree with the cream almost instantly when they are blended.
Adding turnips to the soup sweeten the flavor a little, lighten the texture and make it less starchy, and also help minimize the glue factor.
Leek and Potato Soup with Turnips
4 medium-sized leeks (usually about 1 bunch of leeks, about 4 cups chopped)
3 medium russet potatoes (with the turnips, about 4 cups diced)
2 medium turnips
¼ cup organic heavy cream (grass-fed, if possible)
Fill your kitchen sink or a large bowl with cold water. Trim the root ends and dark green ends off the leeks; I hold them by the white end and then use a knife to sort of shave the dark green outer leaves off into a point. Split the leeks lengthwise down the middle. Swish each half in the cold water thoroughly to and then let them float. Grit and dirt will sink to the bottom of the sink and then you can just lift the clean floating leeks from the top. Chop the leeks into ½ inch crescents.
Peel and dice the potatoes and turnips. The size of the dice isn’t crucial, but the smaller the dice the more quickly they will cook to tenderness and the less blending is needed to make a smooth soup. I try to do about a 1/2 inch dice. If you prefer not to use turnips, use one more potato instead.
Put all of the vegetables into a large heavy bottomed pot with about ½ teaspoon of sea salt. Add enough water to just barely come to the top of the vegetables. Remember, the vegetables will release a lot of liquid as they cook and we don’t want to water down the flavor with too much extra water, and you can always add a little extra if the pot begins to look a little dry. Cover the pot with a lid and bring to a simmer. Cook for 20-30 minutes until all the vegetables are very tender, stirring occasionally. I mash a piece of potato against the side of the pot to check tenderness. It should give no resistance to the spoon when it’s done.
Using a handheld stick blender (my preference), a food processor, or a blender, puree the soup until it is completely smooth and velvety. Add ¼ cup of organic heavy cream, blend until combined and then check for salt. The cream will coat your tongue slightly so it’s best to wait until after adding the cream to add the final salt.
Although I don’t have a slow cooker right now, I see no reason why you couldn’t simmer the vegetables on low in a slow cooker for several hours. Add maybe a little less water to the vegetables and stir once or twice to make sure the sugar in the leeks isn’t sticking, then blend and season as you would with a stove top version.