Ingredients:

  • 1 medium Butternut Squash (approx. 900g / 2 lb), peeled, seeded, and cut into 1-inch cubes
  • 2 Tbsp Olive Oil
  • 1/2 tsp Sea Salt
  • 1/4 tsp Black Pepper
  • 2 medium Leeks (white and light green parts only), thoroughly cleaned and thinly sliced
  • 2 Tbsp Unsalted Butter
  • 2 cloves Garlic, minced
  • 1/4 tsp Ground Nutmeg
  • 1 1/2 cups Vegetable Stock (low sodium)
  • 1/2 cup Whole Milk or Single Cream
  • 1/2 cup Parmigiano Reggiano, finely grated, plus extra for serving
  • 1 Tbsp Lemon Juice (freshly squeezed)
  • Salt and freshly ground Black Pepper, to taste
  • 400 g Dried Spaghetti or Linguine
  • Water and Salt for boiling

Instructions:

  1. Preheat oven to 400°F (200°C). Toss the squash cubes with 2 Tbsp olive oil, salt, and pepper on the baking sheet.
  2. Roast the squash for 35–40 minutes, turning once halfway through, until the squash is very tender, lightly caramelised, and easily pierced with a fork. Set aside to cool slightly.
  3. Thoroughly wash the sliced leeks to remove any trapped grit. Pat dry.
  4. Melt the butter in the large skillet over medium heat. Add the sliced leeks and sauté gently for 8–10 minutes, stirring occasionally, until they are soft and translucent (do not brown).
  5. Stir in the minced garlic and nutmeg and cook for 1 minute until fragrant. Remove the skillet from the heat.
  6. Cook the pasta: While the leeks are cooking, bring the salted water to a rolling boil. Add the spaghetti and cook until al dente. Crucially, reserve about 1 1/2 cups (360ml) of the starchy pasta water before draining.
  7. Blend the Sauce: Transfer the roasted squash and the sautéed leek mixture to a blender (or use an immersion blender directly in a bowl). Add 1 cup (240ml) of vegetable stock and the milk/cream. Blend until completely smooth and creamy.
  8. Adjust Consistency: Pour the sauce back into the empty skillet. If the sauce is too thick, stir in small amounts of the reserved pasta water until it reaches a desired pouring consistency.
  9. Season and Enrich: Heat the sauce gently over low heat. Stir in the grated Parmesan cheese and the lemon juice. Stir until the cheese is melted and the sauce is uniform. Taste and adjust seasoning with salt and pepper.
  10. Combine and Serve: Drain the spaghetti and immediately transfer it to the skillet with the sauce. Toss well for 1-2 minutes, ensuring every strand is coated. If the sauce becomes too tight during tossing, add a splash more pasta water.
  11. Final Presentation: Serve immediately with an extra dusting of Parmesan and freshly cracked black pepper.