Roasted Vegetable Stock

Preheat the oven to 400°F (200°C).
In a large roasting pan, combine the onions, onion peels, carrots, celery, and garlic cloves.
In a small bowl, mix together the miso paste and 1/3 cup of water. Stir this into the vegetables, coating them lightly.
Roast, tossing the vegetables once or twice during cooking, until everything is brown, fragrant, and toasty, 45 to 60 minutes. Keep a close eye on the vegetables towards the end so as not to let them take on a scorched taste.
☞ TESTER TIP: If your vegetables look like they’re drying out or the miso is beginning to burn, drizzle an additional 1/3 cup water over the vegetables while they are roasting.
Pile the roasted vegetables and aromatics in a large pot. Add the shiitake, rosemary, thyme, bay, peppercorns, and kombu, and then pour a little of the 3 quarts of water into the roasting pan, scraping up the caramelized bits stuck to the pan, then pour all that into the saucepan. Add the remaining water.
Bring to a boil, and then reduce the heat and simmer, partially covered with a lid, until the broth is a deep brown color and has a rich flavor, 45 to 60 minutes
Pour the broth through a sieve into a heatproof bowl and let cool.
Cover and refrigerate and use as necessary. It will keep for up to 1 week in the fridge or can be frozen for up to 3 months.