Soup season is upon us and, at this time of year, there’s nothing more satisfying as the weather dips into the colder digits, than a pot simmering on the stove (except maybe a loaf of bread). Potato leek soup, known in France as Potage Parmentier, is a classic, simple soup with just a few ingredients. When blended together it transforms into a perfect meal (the whole is greater than the sum of its parts). Creamy, but light (even more so in this version with the swap of whole milk for traditional cream). Savoury with a hint of sweetness from the slowly cooked alums. And texturally and flavourfully exciting, with the addition of salt and vinegar crispy kale. The crispy kale really does make the soup taste extra special, so you’d be wise not to skip the chips. (And bonus to all the parents out there, 3-year olds in this house can’t get enough of kale “chips”. Maybe you will also have the same luck!)
Easy to prepare, hearty, and nutritious, this is a soup you’ll be making again and again. Keep the base recipe the same and change up the toppings for a fresh twist: top it with croutons, grilled halloumi, garden herbs, crispy bacon, fried leeks, or anything else your heart desires. Or serve it chilled next summer, and call it Vichyssoise. Either way, it’s a winning combination. Before skipping to the recipe though, here’s a little culinary tip to help you become a pro at soup season.
What is a Bouquet Garni and Why Should I Make One?
A bouquet garni is a bundle of herbs tied together with string that is used to flavour liquids like soups, broths, and stews by steeping or simmering it. One end of the string keeps the herbs together and the other end can be tied to the pot handle (a trick I learned in culinary school), making it easier to fish out once it’s done cooking. Parsley, thyme, and bay leaves (shown above and also used in this Potato Leek Soup) are common components of a bouquet garni, but depending on the type of soup you’re making, many different types of herbs, spices, vegetable ends, and other ingredients would work. Instead of using a string, a bouquet garni can be created in the form of a sachet where all the components are tied together in a bundle to contain the seasonings. Ingredients that are hard to tie together, like peppercorns, cloves, or even chilies can be easily tucked into a cheesecloth bundle for the purpose of seasoning. It’s a handy trick that makes easy work of seasoning your soup and even easier work of discarding unwanted stems, leaves, and other worn out ingredients.
Potato Leek Soup with Salt and Vinegar Crispy Kale
- To make a bouquet garni, collect the parsley stems, thyme stems, and bay leaf together and tie into a bundle with a piece of kitchen twine or, like in the photo, a thin strip of cheese cloth, leaving a long enough string on one end to tie to the pot handle.
- If using a standard or high-speed blender, don’t fill the jar more than halfway. Leave the hole in the lid ajar, covering loosely with a clean towel; this allows the heat to escape.
- To make this dish vegetarian, substitute the chicken broth for vegetable broth.
For the Potato Leek Soup
- 2 tbsp (18g) salted butter
- 3 leeks (~ 180g), trimmed, halved vertically, washed, then thinly sliced into half moons (white and light green parts only)
- ½ medium onion, diced
- 1 clove garlic, finely minced
- 1½ lbs (680g) Yukon Gold potatoes, peeled and roughly chopped into 1/2-inch pieces
- 5 cups low sodium chicken broth
- 1 tsp sea salt, divided
- A few grinds of fresh ground black pepper
- 5 sprigs fresh parsley (see notes)
- 3 sprigs fresh thyme (see notes)
- 1 bay leaf (see notes)
- 1 cup full-fat milk
For the Crispy Kale Chips
- 8 kale leaves, tough stems removed and torn into bite size pieces
- 2 tsp (15ml) olive oil
- 1-2 tsp apple cider vinegar
- ¼ tsp sea salt
For the Potato Leek Soup
- Melt the butter in a large pot over medium heat. Add the leeks and onion to the pot and cook, stirring regularly, until soft and translucent, about 8 minutes. Do not let the leeks take on any colour.
- Add the garlic and cook until soft and fragrant, about a minute.
- Add potatoes, broth, sea salt, and pepper to the pot. Stir to combine. Tie the string of the prepared bouquet garni (see notes) to the pot handle (for easy removal) and submerge it into the soup.
- Bring to a boil, cover and simmer on medium low 15-20 minutes, or until potatoes are very soft. Remove bouquet garni.
- For a very smooth texture, purée the soup in a standard or high-speed blender in batches until smooth and creamy (see notes). Alternatively, purée all or half of the soup with a hand-held immersion blender until desired consistency is reached. Transfer to a clean pot.
- Add milk and stir through. Taste and adjust, adding more salt and pepper as needed. If soup is too thin, add more broth to thin it out. If it’s too thin, simmer gently until thickened.
- Top with crispy kale chips (recipe follows).
For the Crispy Kale Chips
- Preheat oven to 350°F (170°C).
- To a medium bowl, add kale leaves, olive oil, 1 teaspoon vinegar, and salt. Toss with hands to coat. Taste and add the remaining vinegar, if desired.
- Place kale leaves on a baking sheet, allowing space between each leaf so that they don’t steam.
- Bake for 7-10 minutes, or until crispy and slightly golden.