Intact, tender vegetables
Rich, complex flavors
Ratatouille is a rustic Provençal specialty that transforms late-summer produce—tomatoes, eggplant, zucchini, and bell peppers—by simmering the vegetables, scented with garlic, onion, and herbs, until they have softened into a rich stew. It’s a satisfying dish that can be served as an accompaniment or even turned into a light main course by topping it with an egg, sandwiching it between slices of bread, or spooning it over pasta or rice.
The problem with ratatouille boils down to one thing: water. More specifically, each of the primary ingredients contains more than 90 percent water. If all that liquid isn’t dealt with somehow, you end up with a wet, pulpy mess of ingredients that are indistinguishable in taste, color, and texture.
To remedy this, many cooks complicate what is already a prep-heavy dish (cutting multiple pounds of vegetables into ¼- or ½-inch pieces is the norm). Techniques like salting, microwaving, and pressing are often used to extract excess moisture. The individual vegetables are then typically sautéed in batches to create some flavorful browning before being simmered to cook off more water.
Recipes that skip these steps and call for simply throwing everything into a pot on the stove fared exactly as I anticipated: They were soggy, mushy, and bland. Surely I could come up with a more hands-off approach that would hold ratatouille to its rustic roots but still deliver complex flavor and tender-yet-toothsome texture.
Oven Me Tender
I definitely wanted to skip any type of pretreatment, and that meant finding a method that could efficiently draw out moisture during cooking. On the stovetop, the heat must be kept low in order to avoid burning the food on the bottom of the pot, but this also means that liquid does not readily evaporate. How about using the oven, where the ambient dry heat would evaporate moisture with less risk of burning?
Roasting the vegetables in batches on baking sheets would be almost as bothersome as sautéing each vegetable individually, so I limited myself to using only a Dutch oven and started with the least amount of chopping that I thought I could get away with. I cut onions, plum tomatoes (meatier than round types, with less watery gel), bell peppers, and zucchini into quarters and an eggplant into eighths, figuring that large pieces would retain their shape and texture better than small ones. I tossed the vegetables with olive oil, salt, and pepper (I’d fiddle with other seasonings later) and slid the Dutch oven, uncovered, into a 400-degree oven. Sure enough, after about 2 hours, the moisture had mostly evaporated and the top layer of vegetables was deeply caramelized. But I wasn’t done yet.
Science: Better Browning in the Oven
In a liquid-y dish like ratatouille, the vegetables can brown only when most of the moisture has evaporated. That’s because the exteriors of the vegetables must rise beyond the boiling point of water (212 degrees) to about 300 degrees, the temperature at which browning occurs. On the stovetop, this can take a long time if the heat must be kept low to avoid scorching. However, in the dry, ambient heat of the oven, evaporation and subsequent browning happen quickly, especially since we sauté the onions and garlic in the pot on the stovetop first, preheating the pot before it goes into the oven. Another benefit of oven cookery is that as moisture evaporates, a dark, flavorful fond develops around the inside edge of the pot. Such a fond would take much longer to develop over the low flame of the stovetop.
It had taken so long for any significant amount of moisture to evaporate from the vegetables that some of them (like the zucchini) were blown out and overcooked. What’s more, any intact pieces were unwieldy to eat. I reduced the vegetable size to more manageable 1-inch chunks, which would cook more quickly but still wouldn’t require too much time at the cutting board. I also decided to jump-start the cooking of the onions on the stovetop, which would cut down the oven time and would give me the opportunity to sauté some smashed garlic cloves before I stirred in the remaining vegetables. These procedural tweaks cut the oven time in half, but even after I stirred partway through, the more delicate vegetables were overdone by the time any browning happened.
The eggplant had even begun to disintegrate, leaving its soft pulp and slivers of peel behind. That was unacceptable. Or was it? If eggplant cooks long enough, its flesh becomes downright silky. Perhaps, I thought, I should embrace eggplant’s texture and allow it to break down completely. It just might make for a creamy sauce to unify the stew.
Cooking in Stages
I decided to peel the eggplant to create a smooth sauce with no distractions, and since tomatoes supply so much juice, I added them (also peeled) to the pot with the sautéed onions, garlic, and herbs and seasonings, knowing that their moisture would evaporate for even more concentrated flavor. I would hold the quicker-cooking zucchini and bell peppers back until near the end of the cooking time.
I put my plan into action. After 40 minutes in the oven, the eggplant, onions, and tomatoes were so meltingly soft that they yielded to gentle smashing with a potato masher, turning them into the velvety sauce that I had envisioned. What’s more, most of the onions and eggplant had become so deeply browned and full of concentrated flavor that I wouldn’t need to worry about getting color on the zucchini and bell peppers. Giving these later additions just a short time in the pot would maintain some pleasing bite to contrast with the smooth sauce.
Secrets to Faster, More Flavorful Ratatouille
Classic ratatouille recipes call for cutting vegetables into small pieces, pretreating them to remove moisture, and then cooking them in batches on the stovetop. Our streamlined oven method eliminates the need for batch cooking and pretreatments—plus, it tastes better.
Streamline the Prep
Chop the onions into chunks and smash the garlic cloves instead of mincing them. A brief stovetop sauté cuts down on oven time.
Give Some Vegetables a Head Start
Add the eggplant and tomatoes and then transfer the pot to the oven where moisture evaporates, flavors concentrate, and browning occurs.
Make an Eggplant Mush
Cook eggplant long enough and it becomes soft and creamy. We exploit this trait by mashing the eggplant (along with tomatoes and onions) into a velvety sauce.
Finish With Freshness
Added to the pot toward the end of cooking, zucchini and bell peppers maintain freshness and bite.
I stirred in the zucchini and bell peppers and returned the pot to the oven for 20 minutes. When I checked, a few pieces of zucchini were still on the cusp of being done, but rather than return the pot to the oven, I simply covered it and let it rest for 10 minutes. Now a paring knife just slipped in and out of the pieces.
I noticed that the pot had a dark ring of fond around the inside edge. When left to sit with the lid on, the steam moistened the fond, so I could easily scrape the browned bits back into the ratatouille, making for a simple but robust flavor boost. For spice and heady fragrance, I also added red pepper flakes, a bay leaf, and herbes de Provence (a French blend usually consisting of dried basil, fennel, lavender, marjoram, rosemary, savory, and thyme). In fact, the dish now tasted so rich that I felt that some freshening up was in order.
The intensely caramelized, almost jammy quality of the ratatouille needed a touch of acid. Although entirely untraditional, a splash of sherry vinegar helped wake up the flavors of the sweet vegetables. Finally, just before serving, I stirred in chopped fresh basil and parsley and gave the stew a glossy drizzle of extra-virgin olive oil. And there it was, a ratatouille that was simultaneously flavorful and easy to make.