One of my favorite ratatouille hacks comes from a fashionable Parisian who taught me that the most convenient way to cook the vegetables is on a sheet pan in the oven. Being already committed to the sheet pan cause, it wasn’t a huge leap for me to give up Julia Child’s saucepan method, which requires the cook to stand over the stove, sautéing each type of vegetable separately before combining them all. Sheet pans in the oven are more of a hands-off affair, and the process allows vegetables with similar cooking times to share the same pan (eggplant and onion in one pan, zucchini, peppers and tomatoes in another).
In this recipe, I’ve taken that basic ratatouille-in-the-oven technique and added a halved chicken to the pan. As the meat cooks, the glorious chicken fat coats and crisps the vegetables, imbuing them with flavor. And the chicken absorbs the heady character of onion, peppers, and herbs. It’s not as laissez-faire as other sheet pan recipes — there’s some rotating of pans so everything cooks evenly — but the combination of crisp chicken skin, fragrant herbs and soft summer vegetables is well worth the work.
Technique tip: If you buy tomato paste in a tube, you won’t worry about what to do with the leftover stuff in the can. Or you can freeze the excess.
Make ahead: You can marinate the chicken halves, uncovered, up to overnight in the fridge.
In a small bowl, mash together the butter, salt, rosemary, thyme, tomato paste and garlic.2.
Using kitchen shears, cut down the sides of the chicken’s backbone to remove it. Keep it for roasting later. Flip the chicken over and cut the chicken in half between the breasts.3.
Rub the butter mixture all over the chicken halves, getting it underneath the skin. Place the chicken halves on a rimmed baking sheet and let them marinate for at least 2 hours, and up to overnight, in the fridge (leave it uncovered, which will help the skin dry out and then crisp up when it roasts).4.
Arrange the racks in the top third, middle and bottom third of the oven. Heat the oven to 450°F.5.
On a rimmed baking sheet, toss together the eggplant, onion, 5 tablespoons olive oil and a big pinch of fine sea salt. Top the mixture with 2 thyme sprigs, 1 rosemary sprig and a third of the bay leaf pieces. Place the reserved chicken backbone in the middle of the baking sheet next to the vegetables and roast on the middle oven rack for 20 minutes, tossing the vegetables after 10 minutes. (The pan will be very full and that’s okay; the onion will reduce as it cooks.)6.
Meanwhile, in a large bowl, toss the zucchini, bell pepper and tomato with just enough oil to coat and add a big pinch of fine sea salt. Divide the vegetables between two rimmed baking sheets and spread them out into one layer. Top each pan of vegetables with half of the remaining thyme, rosemary and bay leaf. Nestle half a chicken in among the vegetables on each pan. Make sure the chicken is resting on the pan, not the vegetables. Drizzle the chicken with olive oil.7.
Place these baking sheets on the top and bottom oven racks (the eggplant is on the middle rack). Roast for 15 minutes. Toss all the vegetables (including the eggplant and onion) and drizzle the chicken with a little more oil. Switch the top and bottom baking sheets (to help evenly brown the chicken) and roast for another 15 to 25 minutes, until the chicken registers 155°F when a thermometer is inserted into the thickest part of the thigh. Keep an eye on the vegetables and transfer any that start to burn to a serving bowl.8.
If the chicken is done but the skin isn’t brown enough for you, broil it for 1 to 2 minutes; then transfer the chicken to a serving platter and let it rest for 5 minutes. Transfer all the vegetables to a serving bowl, discarding the herb sprigs and bay leaf pieces, and toss them well with the pan drippings, any juice from the rested chicken and the basil. Sprinkle the vegetables with flaky salt and plenty of black pepper and then serve them alongside the chicken, with lemon wedges on the side.