Use the ripest tomatoes and the best, freshest olive oil for this ratatouille. (Scott Suchman/For The Washington Post)

I make at least two batches of ratatouille — that Provençal melange of eggplant, zucchini, onions, peppers and tomatoes — every summer. I prepare the first as the season’s sweet red peppers begin to file in and the last as the zucchini trickles out, each batch a celebratory bookend to the season’s height of abundance.

Over the years, in search of a ratatouille ideal, I’ve tried a number of approaches, from stewing everything slowly in one pot to roasting every component separately. Those takes have their virtues, but the results are usually either too diluted for my taste or too transformed, the vegetables stripped of their bright, clear flavors.

The method I eventually settled on takes the middle road. It’s a little fussier than stewing everything in one pot, because I cook two of the vegetables — the zucchini and eggplant, those most prone to sogginess — separately, to keep their textures distinct. The onions, peppers and tomatoes cook in a single pan in succession.

Because the juices that release from the tomatoes can produce a watery dish, and reducing it while the other vegetables are in the pan can overcook everything else, I strain the resulting juices instead, then reduce them separately with basil sprigs until they’re syrupy and richly flavored. The resulting dish is luscious and colorful, with plenty of texture and a rich cloak of a sauce intense with the bright, acid notes of tomato and the perfumed essence of basil. Once made, it anchors our meals for days.

When I spoke to cookbook author and teacher Georgeanne Brennan a few weeks ago about ratatouille, she had just returned to her northern California home from a few-weeks’ stay at her home in Provence, where, she said, the dish was everywhere.

For her own, she likes to pull the eggplant and zucchini — which she grows herself in California and shares with a neighbor gardener in France — when they’re relatively young. They’ll have fewer seeds and denser flesh than more mature specimens and will yield a fuller-tasting dish. Long, slender varieties of Asian eggplant are also a good choice, for the same reason. Likewise, I prefer thinner-skinned pepper varieties over standard bells, again for their density but also for their often more intense flavor,

For this particular version, stick to very ripe tomatoes; not only will their skin slip right off with a paring knife, they will break down more easily in the pot. As for the basil sprigs that reduce in the sauce, don’t tip them into the compost bin after cooking. Slip one into your mouth, or feed them to someone appreciative of their candied savor.

A few words about olive oil: Don’t skimp on it. Ratatouille is a simple dish with pure, straightforward flavors. While it’s true that cooking destroys some of the nuanced flavors in a top-shelf bottle, it also doesn’t destroy the plastic and off-tasting flavors of low-quality oils.

“The olive oil you use is part of the flavor that’s going into the dish,” Brennan says. Low-quality oils, she adds, can detract from your final dish. She recommends looking for harvest and sell-by dates on the bottle, which together tend to be indicators of quality. For an accessible, affordable, good-quality extra-virgin oil, appropriate for ratatouille, she points to the California Olive Ranch brand.

Finishing the ratatouille is when you make it your own. It has a beautiful depth of flavor as is, but you can add any number of ingredients for extra dimension: pitted and chopped olives — green varieties suh as Lucques and Picholine are a good fit here — capers, or mild red chili flakes, such as aleppo and maras. Fans of cookbook author Elizabeth David might recall her fondness for coarsely ground coriander in ratatouille, and if you like that seed’s citrusy, piney notes, it’s a nice touch. The recipe here calls for ample amounts of chopped parsley, but you could use a much smaller amount of traditional or lemon thyme, or a little summer savory, instead.

There is nothing wrong with eating this dish straight. I like to serve it with a bowl of harissa-sauced chickpeas and roasted potatoes, or with hard-cooked eggs and aioli, and some good bread. Brennan serves hers with rice; elsewhere in Provence, she says, it might be served as a main dish, but also as a side to lamb chops, steak or the North African lamb sausage known as merguez. Leftovers make a fine filling for an omelet or a topping for a tartine. And this dish is perfect for a picnic or potluck.

As do most stews — even though this particular version isn’t stewed in the strictest sense — ratatouille is a dish that improves with rest, its flavors mellowing, deepening, interlacing over time. I feel a kind of richness just having it on hand. On its own, it is enough to make a meal feel special.

Horton is a freelance writer living in Seattle. She will join the Free Range online chat on food at noon on July 29 at live.washingtonpost.com.