Ingredients:

  • 4 large Yellow or Spanish Onions (approx. 1 kg / 2.2 lbs), peeled and sliced pole-to-pole, about ⅛-inch thick.
  • 4 Tbsp (60g) Unsalted Butter.
  • 2 Tbsp (30 ml) Extra Virgin Olive Oil.
  • 1 tsp fine Sea Salt, plus more to taste.
  • 1 lb (450g) Rigatoni, Pappardelle, or Tagliatelle.
  • ½ cup (120 ml) Dry White Wine (like Pinot Grigio) OR 2 Tbsp Balsamic Vinegar, if avoiding alcohol.
  • ½ cup (120 ml) Low-Sodium Vegetable or Chicken Stock.
  • 1 tsp fresh Thyme leaves (picked off the stem).
  • 1 cup (100g) finely grated Parmesan or Grana Padano, plus more for garnish.
  • 1 Tbsp freshly cracked Black Pepper.
  • 2 Tbsp cold Unsalted Butter (reserved for the final emulsion).

Instructions:

  1. Prep Ingredients: Thinly slice all onions. Grate the Parmesan cheese. Measure out liquids and stock.
  2. Start the Slow Burn: Place the Dutch oven over medium-low heat. Add the 4 Tbsp butter and olive oil. Once shimmering, add the sliced onions and 1 tsp of salt.
  3. Sweat and Stir (30 minutes): Cook the onions over low heat. For the first 30 minutes, they should soften, release liquid, and become translucent. Stir every 5-7 minutes. The goal is soft, yellow-gold.
  4. Deepen the Colour (15–30 minutes): Increase the heat slightly to medium-low. Continue cooking and stirring every 3–4 minutes. As water evaporates, the onions will begin to stick and turn deep brown (mahogany). Scrape the 'fond' (the browned bits on the bottom) back into the onions; this is key flavour.
  5. Deglaze: Once the onions are a deep, jammy brown and have reduced significantly, pour in the white wine (or balsamic vinegar). Scrape the bottom of the pot vigorously to incorporate any remaining fond. Let the wine reduce fully until almost evaporated (about 3 minutes).
  6. Start Pasta Water: While the onions finish caramelising, bring a large pot of heavily salted water to a rolling boil.
  7. Add Stock and Thyme: Pour in the vegetable stock and add the fresh thyme to the onions. Simmer for 5 minutes, allowing the liquid to thicken slightly into a sauce consistency. Taste and adjust seasoning (add salt if needed). Keep the sauce warm on the lowest possible setting.
  8. Cook Pasta: Add the Rigatoni to the boiling water and cook according to package directions (aim for 1-2 minutes less than al dente, as it will finish cooking in the sauce).
  9. Reserve Water: Just before draining, reserve at least 1 cup (240 ml) of the starchy pasta cooking water.
  10. Combine and Toss: Drain the pasta and immediately transfer it to the pot with the caramelized onions.
  11. Emulsify: Add the freshly cracked black pepper and half of the grated Parmesan cheese. Begin tossing vigorously. Gradually add the reserved pasta water, one ladleful at a time, until the sauce coats the pasta beautifully and is creamy, not watery.
  12. The Cold Butter Finish: Take the pot off the heat. Stir in the final 2 Tbsp of cold butter (this creates a glossy, stable emulsion).
  13. Serve: Serve immediately, topped with the remaining Parmesan and an extra crack of black pepper.