Ingredients:

  • 1 medium (approx. 2 lbs) Butternut Squash, peeled, seeded, and diced into 1-inch cubes
  • 2 tablespoons Olive Oil (for roasting)
  • Kosher Salt & Black Pepper, to taste
  • 1 tablespoon Unsalted Butter
  • 1 tablespoon Olive Oil (for sautéing)
  • 2 Large Leeks (white/pale green parts only), thoroughly cleaned and thinly sliced
  • 2 Garlic Cloves, minced finely
  • ½ teaspoon Dried Thyme (or Sage)
  • 1½ cups Vegetable or Chicken Stock (low sodium), warmed lightly
  • ¼ cup Heavy Cream (or whole milk)
  • Pinch Freshly Grated Nutmeg
  • ½ cup Parmigiano Reggiano, finely grated, plus more for garnish
  • 14 ounces Spaghetti, good quality
  • Reserved Pasta Cooking Water

Instructions:

  1. Preheat oven to 200°C (400°F). Toss the diced butternut squash with 2 tablespoons of olive oil, salt, and pepper on a baking sheet.
  2. Roast the squash for 25–30 minutes, turning halfway, until the squash is tender and the edges are starting to caramelise and brown slightly.
  3. Slice the leeks lengthwise, fan the layers open, and rinse thoroughly under cold water to remove all grit. Slice thinly.
  4. In a large frying pan or Dutch oven, melt the butter and remaining olive oil over medium-low heat. Add the sliced leeks and thyme. Cook slowly, stirring occasionally, for 8–10 minutes until the leeks are completely soft and translucent—do not allow them to brown.
  5. Stir in the minced garlic and cook for 1 minute until fragrant. Remove the pan from the heat.
  6. Bring a stockpot of heavily salted water to a rolling boil.
  7. Add the spaghetti and cook according to package directions, typically 8–10 minutes, until perfectly al dente.
  8. Before draining the pasta, scoop out at least 1 cup (240ml) of the starchy pasta cooking water and set it aside. Drain the spaghetti immediately.
  9. Transfer the roasted squash, the cooked leek and garlic mixture, the warm stock, and the heavy cream (if using) into a high-powered blender.
  10. Blend on high speed until the sauce is absolutely smooth and creamy. Taste and adjust seasoning with salt, pepper, and a pinch of nutmeg.
  11. Return the sauce to the large frying pan (now empty). Stir in the ½ cup of grated Parmesan.
  12. If the sauce is too thick, gradually whisk in reserved pasta water until the desired consistency is reached. It should be creamy and coat the back of a spoon.
  13. Add the drained spaghetti directly into the sauce pan. Toss vigorously for 1–2 minutes to ensure every strand is coated. Serve immediately, garnishing with extra grated Parmesan and black pepper.