Ingredients:

  • 2 Tbsp Unsalted Butter
  • 1 Tbsp Olive Oil
  • 2 large Leeks, white and light green parts only, thoroughly washed
  • 3 cloves Garlic, minced or finely grated
  • 1 tsp Dried Thyme
  • 1 tsp Kosher or Sea Salt, divided
  • 1/2 tsp Black Pepper, freshly cracked
  • 5 lbs Starchy Potatoes (Russet or Maris Piper), peeled and 1-inch diced
  • 1 medium head Cauliflower, trimmed and cut into large florets
  • 6 cups Chicken or Vegetable Stock, low-sodium preferred
  • 2 Bay Leaf
  • 1/4 cup Heavy Cream (Optional)
  • 1 tsp Lemon Juice, freshly squeezed
  • Salt and Pepper, To taste (for final adjustment)
  • 2 Tbsp Fresh Chives or Parsley, finely chopped, for garnish

Instructions:

  1. Prep the Leeks: Slice the leeks thinly, then soak them in cold water for 5 minutes. Swish them well to release any trapped grit, drain thoroughly, and pat dry.
  2. Sauté the Base: Heat the butter and olive oil in a stockpot over medium heat. Add the cleaned, sliced leeks and a pinch of salt. Cook gently for 6–8 minutes, stirring frequently, until soft and translucent—do not brown.
  3. Bloom the Spices: Add the minced garlic and dried thyme. Cook for 1 minute until fragrant.
  4. Build the Soup: Add the diced potatoes and cauliflower florets to the pot. Stir well to coat them in the aromatic base.
  5. Add Liquid: Pour in the stock, ensuring the vegetables are fully submerged. Add the bay leaves and the remaining initial salt and pepper.
  6. Simmer: Bring the liquid to a boil, then immediately reduce the heat to a gentle simmer. Cover the pot and cook for 20–25 minutes, or until both the potatoes and cauliflower are completely fork-tender.
  7. Remove Aromatics: Turn off the heat. Use a slotted spoon or tongs to carefully remove and discard the bay leaves (and any large thyme sprigs).
  8. Blend for Velvety Texture: Carefully blend the soup directly in the pot using an immersion blender until perfectly smooth and creamy. (If using a stand blender, work in batches, filling the blender no more than halfway, venting the lid, and blending until smooth. Return the blended soup to the pot.)
  9. Enrich and Adjust: Stir in the optional heavy cream (or dairy alternative) and the lemon juice. The acid from the lemon brightens the entire dish and is crucial.
  10. Final Seasoning: Taste the soup and adjust salt and pepper as needed. If the soup is too thick, stir in a splash more hot stock or water until the desired consistency is reached.
  11. Serve: Ladle the hot soup into bowls and garnish with fresh chives or parsley.