A simple creamy cauliflower potato soup and finished with an optional topping of frizzled leeks and capers. This soup is incredibly easy to prepare and made with everyday ingredients!
Prepare Soup: Trim the root ends of the leeks. Slice the leeks in half lengthwise, spread apart the layers, and rinse well under cold water to remove any grit. Set aside a 2-inch length piece of one leek half for frying for the soup garnish. Finely slice the remaining leeks.
Heat the olive oil and butter in a large pot over medium heat. Add the sliced leek and sauté for 8 to 10 minutes, stirring occasionally, until the leeks are very soft and almost translucent.
Add the diced potato and saute for an additional 2 to 3 minutes, stirring every minute or so. Add the cauliflower florets to the pot along with the chicken broth and bring to a boil. Lower the heat and simmer the soup for 20 to 25 minutes, uncovered, or until the potatoes and cauliflower are soft and cooked through.
Transfer the soup to a high-powered blender, such as a Vitamix, and blend until very smooth. Transfer the soup back into the same pot, heat over low, and add the lime juice, Dijon mustard, fresh nutmeg, parmigiano-reggiano cheese, and pinch of cayenne. Season the soup to taste with salt and pepper.
Note: Potatoes and cauliflower require a large amount of salt in order to be seasoned properly. If the soup is too thick, add a touch of any leftover chicken broth. Keep the soup on low while you prepare the garnish of frizzled leeks and capers (optional)
Prepare Garnish: Line a small plate with a paper towel and set aside. Take the 2-inch piece of leek that you reserved earlier, splay the layers, and flatten them against a cutting board. Using a sharp knife, slice the leeks lengthwise into very thin strips. Set aside the capers.
Heat roughly 1 cup (240 mL) oil in a small saucepan until it reaches 360°F (180°C). Fry the leeks in small batches, stirring the leeks in the oil with a slotted spoon to ensure they fry evenly, until they are golden brown (this will take anywhere from 10 to 20 seconds per batch). Transfer the leeks to the paper towel lined plate, sprinkle lightly with salt, and allow to cool until very crispy. Repeat with the remaining leeks, followed by the capers. The capers will take slightly longer to fry and will turn light brown in color when done.
Serve the hot soup and garnish each serving with a small amount of frizzled leeks and a few capers.
Tips for Success:
If you choose not to prepare the frizzled leek and caper garnish, finely slice the remaining piece of leek and simply add it to the soup along with the rest of the leeks.