Vegan French Onion Soup
As I recently wrote in my Vegan Miso Soup recipe, I am so excited to discover kombu, the Japanese dried kelp that can be used to make savory vegan soup stocks. Kombu is special because it contains natural glutamic acid, the same amino acid that gives meat its savoriness. It's also great because, if you simmer it for awhile, it loses its seaweed flavor and becomes very neutral and highly adaptable to different cuisines.
French Onion Soup is one of those dishes that vegetarians seem to miss the most. (Many have the common experience of ordering it regularly in restaurants, mistaking it to be vegetarian, until they were regretfully informed that its rich, flavorful base was long-simmered beef or veal stock. Delicious but definitely not vegetarian.)
Even if you're an omnivore, like me, the idea of simmering beef bones for hours to make a decent stock may not be practical. And if, like me, you're trying to cut back on your meat and fat intake, you may have tried buying cartoned vegetable broths, and found them to be weak and strange tasting, expensive, and high in sodium.
Enter kombu. It not only makes a hearty stock for a traditional meat-based soup like French-onion, but contains none of preservatives or "off" flavors you find in prepared stocks. And by the time you caramelize the onions, the delicious stock will be ready, saving you hours of time over traditional beef stock. It's a boon for vegetarians and meat lovers alike, and I think you'll be very impressed by the richness of its flavor.
For about 5 cups of soup, or 3-4 hearty servings, you will need:
- 2 large onions, cut in half and thinly sliced to about 1/4 inch. (I normally use yellow for cooked foods, but if you have red on hand, that's fine too.)
- Olive oil
- Kosher salt
- Black pepper
- 1 tablespoon thinly sliced garlic cloves
- 1 12"x3" piece of kombu, well-rinsed and broken into smaller pieces
- 1/4 t dried thyme, or 2/3 sprigs of chopped fresh thyme
- 2 small bay leaves
- Water
- 1 tablespoon or to taste dry sherry (or a splash of dry white or red wine)
OPTIONAL:
- 3 large button mushrooms, thinly sliced and sauteed in a little salt and olive oil.
- Handful of raw, chopped dark greens (spinach, kale, mustard...)
- Toasted or stale bread slices
- Grated Gruyère, Emmentaler, Jarlsberg, or other good Swiss-style cheese
- Dusting of grated nutmeg
Directions:
Heat 1-2 tablespoons of olive oil in a large skillet over medium heat. Add the onions and coat well with the oil, then reduce heat to medium low. Add 1/2 teaspoon salt and cook for about 20 minutes, scraping the bottom of the pan every 30 seconds or so to avoid burning. As the water from the onions evaporates, you may find that you need to lower the heat further. Add the sliced garlic and the dried thyme. (If you're using fresh, you will add it when you put the onions in the broth.) Continue to scrape the pan regularly and caramelize the onions for another 20-30 minutes (depending on the size of your pan: bigger pan = quicker caramelization) until they achieve a deep golden brown, but do not smell or taste burnt.
Meanwhile, in a large saucepan, bring the kombu and the bay leaves to a boil in 3 cups of water. Reduce to low heat and simmer, uncovered for 30-45 minutes. This will yield about 1 1/2 cups of kombu broth. Remove the kombu pieces and bay leaves and add 2 1/2 cups of water and the sherry or wine. Add the caramelized onions and any greens or sauteed mushrooms you are using. Taste and adjust for salt and pepper. Bring to a boil, reduce the heat to low, and simmer, covered for at least 10 minutes, until the greens are cooked through and soft, and all the flavors in the soup have married.
You may serve as is, or, if you are traditionally inclined, ladle the soup into broiler-safe bowls or ramekins. Top with toasted bread, and cover generously with shredded cheese and a dusting of nutmeg. Place under an oven or toaster oven broiler until the cheese is melted and browned. Serve immediately.