My grandmother’s way with summer’s pebble-skinned, canary yellow crookneck summer squash, which she grew in the neck of the Florida Panhandle, was to cook it with browned onions until it was falling apart, then cook it a little bit past that. It came out of the pot spreadable as jam, concentrated and melting, its sweetness hemmed by lashings of black pepper.
Hers is the approach I have in mind when I cook summer squash and zucchini, cut into thin discs and braised slowly just until they start to collapse. I love squash other ways, too — grated raw for an herb-strewn salad or seared in a hot pan until its edges caramelize to a deep burnish — but nothing quite captures its buttery, creamy flavor like sweating it in its own juices.
Cooking vegetables to total tenderness — until, some would say, they’re done — isn’t the American way with the vegetables of summer. Braising and stewing and sweating are techniques we turn to in cooler months, when spending time at the stove feels more respite than duty. In the hot months of August, our inclination is toward the salad bowl and the grill, for summoning sensations of taste and texture that contrast, rather than align, with the summer heat and humidity.
But look to the silky braised greens of the deep South, or the slowly caramelized medley of peppers, onions and zucchini known in Turkey as marmouma, or the sweet and creamy eggplant-sauced pastas of Italy, and you’ll see a powerfully delicious reason to keep summer vegetables on the stove. Cooking vegetables low and slow develops flavors that brief cooking merely skims. It coaxes them into denser, sweeter, more mellow and yet more intensely flavored versions of themselves.
My favorite example of this transformation is the flat, mossy-hued green bean typically referred to as a Romano bean. Even when raw, this type of bean can have remarkable depth of flavor; the integrity of its snap is something to marvel over. Sauteed or steamed until al dente, its character is little moved, the flavor still a little grassy, its juicy crunch subdued but still intact.
Cooked slowly over a gentle flame for an hour or more, with a little garlic, a glug of oil and a few tablespoons of water, Romanos are transformed. They are dense and meaty, exquisitely beany, the texture tender and supple. They beg to be eaten from the pot over the stove, from the refrigerator with fingers. Paired with some good cheese and a hunk of bread, they can stand in for dinner on a low-key night.
The same general idea can be applied to zucchini, string beans, green peas, asparagus, leafy greens, bell peppers, broccoli, cabbage, fennel.
For every vegetable, the precise cooking time and the amount of liquid you may add will vary depending on variety, age and size. “It’s not really about length of time; it’s more about the yield that determines when they’re done. Each vegetable will tell you,” says chef and author Gabrielle Hamilton.
She compares soft-cooked vegetables to slow-cooked meat, clarifying that the process isn’t about overcooking: “It’s about opening the vegetable up until it starts to get juicy and starts to run and has a more slippery and delicious quality.”
If the heat is too high, the vegetables will cook unevenly, breaking down before sufficiently cooking through. Too much water, and they’ll leach much of their flavor into the cooking liquid — a recipe for good pot liquor, but only if you’ll be drinking it.
Too much of both is just a short step away from boiling, a likely cause of many long-held vegetable grievances. It’s also the surest route to nutrient loss, as those vitamins go into the cooking liquid, too. But there’s an easy fix: “If the cooking water is to be consumed as a part of the dish . . . then overall nutrient retention will be high, regardless of temperature (usually simmering) or time,” Robert Parker, professor of nutritional sciences at Cornell University, told me in an email.
So use as little liquid as possible, and serve the vegetables with their concentrated juices. The heat should be low to moderate, the liquid barely enough to burble around the vegetables’ contours. If your vegetables are juicy enough to start, you may not need liquid at all.
Higher-water-content summer squash or broccoli will soften more quickly than denser, lower-water-content choices such as kale or pole beans, but this is not a process to rush.
My favorite recipes for long-cooked vegetables take around an hour on the stove, but it’s a relatively idle one; they mostly take care of themselves, as long as you’re free to offer a turn of the spatula every now and again.
One advisory: Best not to look to this method as a means of salvation for produce that should have been cooked days before.
You can, to a degree, hide a tired vegetable’s shortcomings by overwhelming it with other flavors, whether in a soup, a stew or a vegetable stock, although it won’t pull its own weight in contributions to the dish.
When that vegetable is standing alone, there’s nothing to hide behind, not heat or salt or fat. Those things only amplify what you have to begin with, so the more you have — the more you have. (If you don’t believe there’s much to suffer in cooking old veg, try braising some just-harvested greens alongside a bunch you purchased a week ago and comparing the results.)
What you should assign to this approach are your oversized and overgrown, those mature specimens whose time on the vine or the stalk has left them deeply flavorful but a little callous. Cooking them slowly and gently lends them some grace and puts a finer point on their complex flavor.
This is especially apt for leafy greens, particularly brassicas such as turnips, cabbage, mustards and kale, which often lose sweetness and tenderness while picking up pungency in the summer heat. It’s in a covered pot this season, not a salad bowl, that they find realization, and some submission.
My favorite recipes will give you a starting point. Try them on a rainy day or a cloudy one. Pair them with something raw, something steamed, something fried; the diversity itself will be refreshing. Then, if you’re fortunate enough to have extra, put up some summer vegetables in the freezer. In the deep of winter, cooked slowly until their flavors deepen, they will issue promises of what lies ahead.
Horton is a freelance writer living in Seattle.