ASK Christine: Alliums

I had two questions this week about alliums:

Adam said “I am not entirely sure what the difference between green onions, spring onions, and chives are. Oh, and then there’s leeks….” and then Becky asked “what type/color of onion is best for fajitas?”

Alliums are the plant family that includes onions, garlic, chives, leeks, shallots, and scallions. There are two broad categories by which I divide types of alliums: plants cultivated for their roots and plants cultivated for their tops.

Bulb onions are part of the foundation of most cooking. They are part of the French mirepoix, the Creole and Cajun holy trinity, Spanish sofrito; from West Africa to India to Germany you find onions as one of the basic flavor of nearly every culture’s cuisine.

The common, everyday onion is cultivated for its round bulb root, as are shallots, cipollini onions, sweet Vidalia and Walla Walla onions, and red, yellow, and white onions. The bulbed spring onions sold in bunches with green tops intact are bulb onions that have been thinned out or harvested young. Bulb onions tend to have tough green tops which are typically not eaten. Bulb onions are harvested and dried before being used since moisture can cause them to rot; sweet onions like Vidalias have a higher moisture content than their more pungent cousins which makes them more perishable. That difference is also something to take into consideration when you choose which onion you will use; if you don’t want extra water releasing from the onion into your food, you need to either choose a dry variety like the white or yellow onions you find in the grocery store or cook the moisture out first. Dry bulb onions can be kept in a cool dark spot; sweet onions, garlic, and spring onions will keep better in the bottom drawer of the refrigerator.

Alliums grown for their tops and flowers are used more as herbs, fresh and raw, used as a more delicate flavor enhancement at the end of preparation than cooked into a dish. Chives and scallions are cultivated primarily for their green tops; their milder flavor and tender greens make them more palatable raw. Chives, scallions, and garlic chives, are delicate and much more perishable than bulb onions, so keep them wrapped in a paper towel in a bag in the crisper drawer and use them within five days or so before they wilt.

Leeks are a bit of a middle ground allium. They have a delicate savory flavor but are usually used cooked, their tougher upper leaves trimmed. They have the slender shape of a scallion with no bulbous root at the end but are not harvested young like scallions.

The pungent heat from any allium can be tempered in one of two ways: with a soak in something acidic like vinegar – shallots in vinaigrette for example – or by the application of heat – garlic roasted to sugary sweetness.

 I hope this was a good overview from which to start getting to know such a ubiquitous plant family a little better.

An Update: Leek and Potato Soup with Turnips

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

 serves 4-6

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

Water

Sea salt

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.

Potato Leek Soup

It is Allium season. All of the plants that spent the rainy winter in the ground are burgeoning in the warm weather, blooming and ripening. In the garden and farmers markets, broad hipped rosy red onions, mauve puffball chive blossoms, elegant jade leeks, sweet cloveless young garlic.

Weyland from a couple of plots over offered me some of his leeks. He had a beautiful row of slender leeks he planted last Fall and said he didn’t really know what to do with them. I told him how to make potato leek soup, how easy and good it was so he took them home to try the recipe. A few days later, I asked him how the soup had turned out and he said it was great, they had made it 3 times. He was digging more leeks (and not offering me any) so I guilted him into giving me a nice handful.

I think the reason that the Mesdames Child and Beck began Mastering the Art of French Cooking with a recipe for potato leek soup is that it is the sort of recipe that can be related while standing in a garden with a shovel in your hand. It is essentially simple without being plain, and delicious without being difficult.  It always pains me to see new cooks start out with a difficult dish and then become discouraged when it doesn’t turn out well. This soup on the other hand is a great confidence builder.

While the basic recipe requires only five ingredients- potatoes, leeks, water, salt, and cream- I sometimes augment or adapt it by adding some turnips and substituting chicken stock for water or milk for cream. The crucial step is to get all of the vegetables scrupulously clean. Leeks are notorious for hiding grit amongst its cracks and crevices. I get it all squeaky clean by first cutting off the darker green tops of the leeks, then quartering them and rinsing them in a bowl of water deep enough for the dirt to settle on the bottom while the leeks are being swished around above them.  Be thorough, because “earthy” isn’t the flavor we’re going for this time.

After the leeks are clean, chop them into chunks. Peel and cut the potatoes into large chunks. Dump them into a pot; add a generous amount of salt (although you will want to leave room to adjust it later) and just cover with water. Cover the pot and bring it to a low boil and cook for 20 minutes or so, until the leeks have softened and the potatoes are tender enough to crush with a fork. Using an immersion blender or canister blender, puree until quite smooth. Pour in cream, bit by bit, tasting as you go. I tend to use very little cream, just enough to enrich with out obscuring the flavor of the vegetables. Taste for salt and soup is ready. I drizzled a little olive oil and chives on top- but that embellishment is entirely optional.