One of the best dinners that you can make with the vegetables you probably already have on hand doesn’t even require a pot of boiling water. Just a pot of simmering water.
It’s rustic, beautiful vegetable soup, and if you think that means a pull-out-your-biggest-pot, throw-everything-in-at-once, bring-it-all-to-a-rolling-boil affair, then a new world of soup-making awaits you. It’s much more nuanced, yet still incredibly easy to prepare.
One of the most important things that I’ve come to realize about vegetable soup is that the vegetables are not boiled -- they’re more like poached. (It seems so obvious, especially since the same basic principle is applied to making meat stock so that it doesn’t get cloudy, but for me, it was a light-bulb moment.) For most of the cooking time, the water is barely even simmering. It’s hot, and there’s steam coming from the pot, and the water bubbles only occasionally. It’s what the French call not “simmering” but “shivering.”
The result is that the vegetables maintain their integrity; their taste and textures are fresh and distinct. Aromas and flavors are gently coaxed from the vegetables. (And the peels don’t come away from the potatoes. I hate it when that happens.)
Veggies the stars
Instead of soup being a last resort to use up whatever vegetables are sitting in the refrigerator going to waste, it is a way to respect vegetables and to bring out the best in them. Once I got that into my head, I wanted to make vegetable soup all the time.
That soup also happens to be one of the most improvisational dishes in the universe is a bonus. It means that it doesn’t require a lot of forethought -- no need to go down a precise checklist of ingredients while you’re at the store. Use whatever catches your eye at the market -- chard, rutabaga, purple-top turnips, you name it. But even if you have only onions, garlic, potatoes, carrots, some herbs, you’ve got soup.
And though soup often is considered an appetizer, a soup full of vegetables makes an excellent main course -- especially when it’s finished with a dollop of garlic-herb paste that you swirl into the soup, which gives it a big exclamation point of flavor and color. Add a few fat cubes of croutons that have been crisped in garlic- and herb-tinged olive oil or butter, and you have a fragrant, filling, comforting dinner in a bowl.
Another integral soup lesson learned is that you make it in stages; its ingredients don’t get dumped simultaneously into one big pot.
It cooks fairly quickly (in less than 30 minutes), so you don’t have to feel obligated to make a pot of soup big enough to feed an army, but it does keep well, covered and refrigerated.
Aromatic vegetables are key, as these are the flavor base for soup -- mainly onions and garlic, but to these you can add leeks, fennel, diced carrots or celery. These are cooked slowly in a little fat; for vegetable soup, olive oil is great. (But if I happen to have cured pork around -- bacon, pancetta, prosciutto -- I’m going to use it unless vegetarians are invited for dinner. It adds flavor and renders some of its own fat.)
Season the soup in stages. A little salt and pepper added to the aromatics goes a long way. (Add a bit more once the liquid is poured in. And once the soup is finished, you can adjust the seasoning to taste.)
Add herbs -- fresh, woodsy herbs that are just waiting to be put into soup, such as rosemary, thyme, savory, marjoram.
A bouquet garni of herbs tied together with kitchen string is a good idea, but you also can drop in a couple of sprigs of one type of herb if that’s all you have, along with a bay leaf.
A vegetable soup is sort of like an ensemble cast. Every vegetable’s a principal player, but each gives a different performance. Some work better together than others. And there are some whose on-set behavior or tendency to chew up the scenery mean you shouldn’t give their agents a call.
Potatoes and winter squashes can ground a soup, their starchiness giving the soup heft. Carrots are solid too, and lend their sweetness. Celery is an excellent aromatic and has a savory, almost salty note.
Be careful of distinct, strong flavors, such as asparagus, some mushrooms and cilantro. Be really careful about most cruciferous vegetables (cabbage, broccoli, Brussels sprouts) because they have strong flavors and take a long time to cook, so they can take over a soup. (One exception for me is rutabaga, because I love its texture and earthy flavor.) Avoid red beets because their color bleeds, but white beets are available at farmers markets.
Summer tomatoes can transform a soup, adding their bright acidity and color; in winter, substitute canned. Leafy greens are great, even the cruciferous kind (such as kale) since they don’t cook long.
Not all vegetables cook in the same amount of time. And they should be cut into uniform pieces, so that they cook evenly. Potatoes and carrots are hard and dense, so those go in first. (Potatoes usually take about 20 minutes to cook.) Beets too.
Vegetables that are less dense, such as crisp-textured turnips and rutabaga, I’ll put in after the water has come to a simmer and then been turned all the way down to “shiver” over low heat.
Any greens -- kale, chard, beet greens -- go in during the last five minutes of cooking.
It’s probably sacrilege to call everything that I put into the herb-garlic paste that gets added to my soup a pistou, but that’s where the idea comes from.
Traditionally, it’s basil, garlic and olive oil, pounded in a mortar. But I’ll shamelessly use just about any combination of herbs and/or greens to make it -- parsley, mitsuba, sage, arugula, even a little chard -- and I’ll do it in the food processor (and add a little mustard for its complex pungency). Sometimes it’s creamy like a pistou or a salsa verde, sometimes it’s drier, like a gremolata.
However you make it, it’s perfect in soup, the raw garlic mitigated by the heat of the broth and the herb sauce brightening the whole dish. It swirls into the soup, the flecks of herbs dispersing their way across the bowl of earthy, delicious vegetables. It’s genius.