Roasting is the secret for rich and hearty vegetable broth. When seasoned well, we find this veggie broth just as satisfying as bone broth. Think of the recipe below as a guide and feel free to add any vegetable scraps in your fridge or freezer. Leeks, turnips or mushroom scraps are all excellent when added to the broth. For even more richness, we add dried mushrooms — these can be purchased online and are often found in the spice aisle of larger grocery stores. They pack a punch and add a “meatiness” to the broth.
1 pound onion (3 medium)
1 pound carrots (5 to 6 medium)
1/2 pound celery (4 to 5 ribs)
1 pound tomatoes (4 small)
4 garlic cloves, smashed and peeled
2 tablespoons olive oil
1/2 ounce dried mushrooms such as porcini, oyster or shiitake
Half bunch fresh parsley, leaves and stems or just use the stems
3 sprigs fresh thyme
2 bay leaves
1 to 2 cups vegetable scraps from fridge or freezer, optional
1 teaspoon sea salt, optional
12 cups water, preferably filtered
Heat oven to 425 degrees F. Grab a rimmed baking sheet or a 9-inch by 13-inch baking dish for roasting the vegetables.
Peel onion and roughly chop into 1-inch chunks. Scrub carrots and celery clean and cut roughly into 1-inch chunks. Rinse tomatoes and if they are large, half or quarter them. Add onion, carrots, celery, tomato, and the garlic to baking sheet or pan. Toss with olive oil then roast 15 minutes. Stir vegetables and roast another 15 minutes. Stir once more then roast until the vegetables are nicely browned and the tomatoes are caving in, another 10 minutes or so.
Cover dried mushrooms with about 1/2 cup of cold water and set aside for 5 minutes.
Spoon the roasted vegetables into a tall stockpot. Add 1 cup of water to the baking sheet or pan then stir it around, scraping up as much of the browned bits stuck to the bottom as you can. Pour over the vegetables in the stockpot.
Add the parsley, thyme, bay leaves, vegetable scraps you need to use up, and the salt (if using). Add the partially rehydrated mushrooms then pour the water they are sitting in through a fine mesh strainer to catch any grit. Add the strained mushroom water to the pot with vegetables.
Cover with 11 cups of water. Bring to a boil, then reduce to a simmer. Cook, partially covered, for 45 minutes. Strain broth and use immediately, refrigerate up to 3 days, or freeze up to 3 months. When using, taste the broth and adjust the seasoning with additional salt or if you are okay with using it, a few dashes of fish sauce.