Ingredients:

  • 2 large onions, unpeeled and quartered (300g)
  • 3 large carrots, cut into 2-inch chunks (200g)
  • 4 stalks celery, including leaves, cut into 2-inch chunks (150g)
  • 1 head garlic, halved crosswise (50g)
  • 2 tablespoons tomato paste (32g)
  • 2 tablespoons neutral oil (30ml)
  • 4-5 pieces dried shiitake mushrooms (15g)
  • 3 quarts cold filtered water (2.8 liters)
  • 1 large leek, green parts only (100g)
  • 6 sprigs fresh thyme
  • 1 small bunch parsley stems
  • 2 dried bay leaves
  • 1 teaspoon whole black peppercorns (5g)
  • 1 small strip kombu (optional)

Instructions:

  1. Preheat your oven to 425°F (220°C).
  2. On a large rimmed baking sheet, toss the quartered onions, carrots, celery, and halved garlic with neutral oil and tomato paste until evenly coated.
  3. Roast for 25–30 minutes, turning halfway through, until the vegetables are deeply browned and the tomato paste has caramelized and darkened.
  4. Transfer the roasted vegetables and all scrapings from the baking sheet into an 8-quart stockpot. Add the dried shiitake mushrooms, leek greens, thyme, parsley, bay leaves, and peppercorns.
  5. Pour in the cold filtered water. Bring to a gentle simmer over medium-low heat. Do not let it reach a rolling boil to ensure clarity.
  6. Maintain a gentle simmer for 45 minutes. If using kombu, add it for the final 10 minutes of simmering.
  7. Strain the broth through a fine-mesh strainer lined with cheesecloth into a clean container. Discard the solids.