The delicate, mild onion flavor of leeks is the perfect match for this thick hearty soup. With a rich and creamy texture, the classic French recipe, Leek and Potato Soup served with a piece of crusty bread is an ideal winter warmer, perfect for a chilly evening. Much like a baked potato, my Leek and Potato soup recipe is the perfect vehicle for garnishes such as cheese, bacon, and a drizzle of sour cream and chives. When pureed and served chilled, the soup became famous by the name Vichyssoise.
What are Leeks?
- Leeks are a member of the Allium family, which includes shallots, chives, onions, and garlic. The flavor is very distinct and subtle without the intense pungent qualities of onions. Their delicate characteristics and great texture make them excellent in soups where a more refined flavor is needed.
- Once snubbed by the aristocracy in Europe. Between the 16th-18th centuries, the leek was considered peasant food, and was dubbed ‘the poor man’s asparagus’.
- It is the National symbol of Wales, during the Hundred Years War from the 13th-14th centuries, the leek was worn by the Welsh soldiers in battle to distinguish themselves from the enemy.
- Leeks can grow to an enormous size but can get very woody if not harvested. Leeks should be harvested when around 12-inches tall and 1-inch in diameter.
- It is very important to thoroughly wash leeks to remove the soil that is caught between the white parts. When preparing the leek, cut away the darkest, tough green parts and cut the leek from the base to the top, leaving the root intact. Rinse the leek under cold running water, separating the leaves to rinse the grit and debris away. It’s a good idea to place the chopped leeks in a colander and give it a final rinse before adding to the recipe.
The French Chef Louis Diat grew up in a small town near Vichy, where his mother would serve leftover Leek and Potato soup chilled. Naming it ‘Vichyssoise’ he introduced the chilled soup to America while he was working at the Ritz-Carlton in New York City, where it became an instant success. Pureed smooth the finished soup is nearly white. Vichyssoise is made from only the white parts of the leek, with white pepper and a clear stock to preserve its appearance. This elegant soup was served in the blistering hot New York summer in the days long before air conditioning.
What type of Potato to use for Leek and Potato Soup?
- A high starch potato such as a Russet or Yukon Gold is needed for this soup. The starch helps to thicken the soup and gives it a creamy texture and look. The real question now is: do you leave the skin on or peel it?
- For Vichyssoise, use Russet potatoes and definitely peel them, you want a beautiful pristine white color, but do not wash them after peeling, you don’t want to rinse away any starch.
- For a Puree soup (called a Potage Parmentier) I would also peel the potatoes
- For a chunky, country-style Leek and Potato soup like my recipe, that has other veggies or herbs in it, I do not peel the potatoes, there are too many good vitamins and minerals in the skin to throw out. Just give them a good scrub and dice the potatoes small enough so the peels aren’t intrusive to the person eating it. I don’t think Julia Child would like the skin left on, but I’m a rebel, haha.
Variations for Leek and Potato Soup
I like to add carrots and flat-leaf parsley to my soup recipe as listed below. Here are some other variations you might enjoy:
- Broccoli and Cheese: Add 3-cups broccoli florets during the last 10-minutes of cooking, remove from the heat and stir in 3-cups of shredded cheddar cheese until just melted
- Spinach or Watercress: During the last 5 minutes of cooking, add 2-bunches of watercress that has the tough stems removed and has been finely chopped. Remove from the heat and stir in ½-cup of heavy cream. Garnish with a few fresh leaves.
- Beer, Cheese, and Sausage: Brown 1-pound crumbled sausage, substitute 2-cups of dark beer for 2-cups of chicken stock and add 8-ounces of shredded cheddar cheese just before serving
- Garnishes: Think of a baked potato when it comes to garnishing Leek and Potato Soup, the flavors work exactly the same. Sour cream, cheese, crispy bacon, chives, and croutons all work really well
- Veggies: Leek and Potato soup is an excellent vehicle for leftover roast veggies. Cauliflower, Brussels sprouts, squash or even roasted potatoes are a great addition.
Vichyssoise and Food Safety
Chilled soups with a high protein content have the potential to be hazardous if not handled properly. Because it is not reheated before service, it is important that Vichyssoise is chilled rapidly to a temperature below 40°F (4°C) as soon as cooking is complete.
Homemade Chicken Stock
I highly recommend my Instant Pot Homemade Chicken Stock for this recipe. Rich and flavorful with a complex, depth of flavor that you simply cannot get from the store-bought chicken stock. Now with Instant Pot technology, a recipe that used to take 5-6 hours of slow simmering can now be accomplished in 45 minutes.
Leek and Potato Soup
- Heavy Bottomed Pot
- 2 Tablespoons Olive Oil
- 4 Cups Leeks 1/2-inch dice, well rinsed
- 1 1/2 Cups White Onion Diced
- 2 Pounds Yukon Gold or Russet Potato 1/2-inch dice
- 1 Cup Diced Carrots
- 2 Tablespoons All-Purpose Flour
- 6 Cups Chicken Stock
- 1 Teaspoon Salt
- 1/2 Teaspoon Black Pepper
- 1 Bunch Flat-Leaf Parsley chopped, stems removed
- 1/2 Pound Bacon Crispy, 1/2-inch dice
- Trim the leeks of the toughest dark green parts. Cut lengthwise into quarters and rinse well under running water. Cut into ½-inch pieces for soup. If still sandy, place in a colander and rinse again.
- Add olive oil, diced onions, and leeks to a heavy-bottomed pot and sauté for 5 minutes until softened
- Add diced potatoes, carrots, 1-teaspoon salt, pepper, and all-purpose flour, stir well to coat everything in flour
- Add chicken stock and bring to a boil, reduce heat to low, cover and let simmer for 30 minutes
- Chop parsley before the bacon to prevent cross-contamination, set aside
- Dice bacon, cook until crispy, drain the oil
- Once soft, smash some of the potatoes with the back of a wooden spoon and stir until the soup thickens to your desired consistency
- Add chopped parsley, serve garnished with crispy bacon