Ingredients
Equipment
Method
- Prep the Leeks: Trim off the dark green tops and roots of the leeks. Slice the white and pale green stalks in half lengthwise, then cut them into thin slices. Submerge the sliced leeks in a bowl of cold water to wash away any trapped dirt or sand, then drain and pat dry.
- Sweat the Aromatics: Melt the unsalted butter in a large heavy-bottomed saucepan or Dutch oven over medium-low heat. Add the cleaned leeks and diced yellow onion. Cook slowly for 10 to 12 minutes, stirring frequently with a wooden spoon, until the vegetables are completely soft and translucent. Do not let them brown.
- Simmer the Potatoes: Add the peeled, diced potatoes, chicken stock, kosher salt, and white pepper to the saucepan. Increase the heat to bring the mixture to a gentle boil, then lower the heat to maintain a simmer. Cover the pot and cook for 20 minutes, or until the potatoes yield completely when pierced with a fork.
- Purée until Smooth: Remove the pot from the heat and let the soup cool slightly for 10 minutes. Carefully transfer the mixture in batches to a high-powered blender. Blend on high speed for 1 to 2 minutes until the soup is completely smooth and liquid.
- Strain the Soup: Position a fine-mesh sieve or chinois over a large bowl. Pour the blended soup through the strainer, using a silicone spatula to press the liquid through while discarding any fibrous bits left behind.
- Chill the Base: Cover the bowl tightly with plastic wrap and place it in the refrigerator to cool completely for at least 4 hours, or overnight.
- Add Cream and Serve: Right before serving, stir the cold heavy whipping cream directly into the chilled soup until fully incorporated. Taste and adjust seasoning with extra salt or white pepper if needed. Ladle into cold chilled bowls and garnish with chopped fresh chives.
Notes
Do Not Brown the Vegetables: Keeping the heat low while sweating the leeks and onions is critical. Any browning will ruin the pale, ivory color and introduce a dark, caramelized flavor profile that masks the delicate allium taste.
Potato Selection: Always use high-starch potatoes like Russet or Yukon Gold. Their natural starches break down easily during blending, giving the soup its signature body without becoming sticky or gummy.
Adjusting Density: Chilled soups tend to thicken significantly as they sit in the fridge. If the soup feels too dense after adding the cream, simply whisk in a splash of cold milk or stock until you reach your desired consistency.
Potato Selection: Always use high-starch potatoes like Russet or Yukon Gold. Their natural starches break down easily during blending, giving the soup its signature body without becoming sticky or gummy.
Adjusting Density: Chilled soups tend to thicken significantly as they sit in the fridge. If the soup feels too dense after adding the cream, simply whisk in a splash of cold milk or stock until you reach your desired consistency.