Head over to France, talk to the first chef you find who's wearing fancy pants, and ask them what the most important ingredient in their kitchen is. The likely answer? Good stock. Now hop on over to Japan, talk to the first itamae you find who's wearing a fancy kimono (OK, Japanese chefs don't wear kimono), and ask them the same. The likely answer? Good stock. Notice a theme?
It's the real backbone of the kitchen, adding bringing out the natural flavors of foods and adding a splash of richness and complexity in ways that plain water can't. A good meat-based broth is pretty simple. Just throw some bones in a pot, add some vegetables, cover with water, and simmer until done. Heck, even canned chicken broth will do in a pinch. Good vegetable stock, on the other hand, is harder to come by.
Have you ever participated in a store-bought vegetable stock taste test? I have, and it wasn't fun. Most are strangely sweet with dried herb flavors or other off-notes. Here's the good news: Great homemade vegetable stock is dead simple to make. Not only that, it can be done in about a quarter the time of a meat-based stock.
I don't really want to get into the muddy details of nomenclature between broth and stock, whether it's got bones or just meat, how much gelatin it has, etc. It's a constant source of debate amongst comestiblely-inclined pedants (not to mention pedantically-inclined cooks), and not one worth entering into. A soup by any other name would taste as hearty, and all that.
I use the words pretty much interchangeably, though I lean towards "stock" if I mean something pretty rich that I'm gonna cook with and "broth" if I mean something my noodles or peas are already floating in. In this case, I'm calling this a vegan stock, as it's as tasty, layered, and full of rich flavor as any meaty broth I've had. It can form the backbone to any number of excellent vegan dishes, be they soups or stews, or even used in basic pan sauces or to moisten or glaze vegetables and pasta.
Today we're going to use this to make a hearty winter vegetable stew.
A very basic vegetable broth can be made with traditional mirepoix. Carrots, onions, and celery are used together often for a reason. Onions add their signature pungency and a touch of sweetness that gets picked up and enhanced by the carrots. Celery comes through with slight bitterness and vegetal notes.
To up the complexity of my broth, I like to use a mix of alliums—yellow onion, leek tops, and a couple of smashed garlic cloves. Herbs play an important role too, adding complexity to the aroma. Parsley stems and leaves add a bit more of the vegetal bitterness, while thyme gives it a savory aroma that I associate with roasting vegetables or braised dishes. A couple of dried bay leaves are also key, their distinct subtle eucalyptus aroma bringing richness and depth to the mix.
For spices, I go with a mix of black pepper, a touch of fennel seeds, and coriander seed. None of them are so assertive as to completely take over (I experimented with star anise and every soup I made ended up tasting like pho).
All of this is great, and it can make for a decent base for glazing vegetables or cooking, say, risotto. But for a really rich, hearty winter broth—the vegan equivalent to a roasted chicken broth, say—I wanted something with deeper color and a bigger umami kick to it.
Where do I turn when I want umami? Glutamates, the compounds that trigger the sensation in our brain. There are plenty of good natural sources of glutamates, many of them vegan. The biggest suspect? Kombu and dried mushrooms. Kombu, giant sea kelp, is the base of most Japanese stocks, prized for the savoriness it brings to them (for many years, kombu was actually used to synthesize monosodium glutamate powder). I wondered if such a Japanese ingredients would be out of place in what is essentially a Western stock, but I needn't have.
The stock I ended up with after adding a handful of dried mushrooms and a piece of kombu to the broth was a deep mahogany brown color with a complex aroma and flavor as deep as any meat-based stock I've ever made. Why the heck can't they bottle this stuff and sell it instead of the junk in the supermarkets these days?
Once you've got a good stock, your soup is essentially made. All it takes for a good vegetable soup is to simmer, well, vegetables in it until they're cooked. I went back for my mirepoix mix—leeks, carrots, and celery—along with a handful of chickpeas, a big bunch of kale (cooked down until completely tender), and some diced potatoes.
There is one thing that bone-based stocks have that vegetable stocks do not: gelatin. As animal bones simmer, touch connective tissue gets converted to gelatin, adding body to stocks. It's what causes a rich chicken stock to turn into jell-o in the fridge overnight. A vegetable broth will always be thin.
To combat this problem in my soup, I used a combination of two techniques. First, I added a very small amount of a cornstarch slurry to the mix. Just enough to add body without tasting starchy or slimy. Second, I used a technique I learned by making Ajiaco, a Colombian potato soup with my wife's aunt. In that dish, potatoes are cooked to the point that they are falling apart at the edges. The resulting released starch thickens the soup into a rich, hearty broth.
Finally, a dash of soy sauce added even more of an umami hit, while a splash of lemon juice added just before serving brightened the whole affair. The result is a 100% vegan soup with rich, complex flavor, a hearty broth, and a flavor that even omnivores will love. I've just found a new winter staple for my wife's lunch box.