Roasted Chicken Breasts With Harissa-Coriander Chickpeas

2 ½ pounds bone-in, skin-on chicken breasts
6 tablespoons extra-virgin olive oil
Kosher salt and pepper
½ cup finely chopped onion
1 teaspoon minced garlic
2 tablespoons harissa paste, more to taste
1 tablespoon coriander seeds, crushed using a mortar and pestle, or 1 1/2 teaspoons ground coriander
1 (15.5-ounce) can chickpeas, rinsed and drained
2 tablespoons fresh lemon juice
¼ cup coarsely chopped parsley

Heat the oven to 450 degrees. On a rimmed baking sheet, combine the chicken and 2 tablespoons oil. Season with salt and pepper and toss to coat. Arrange the chicken in an even layer, skin side up, and roast until golden and cooked through, 30 to 40 minutes, depending on the size of the chicken breasts. Transfer to a cutting board and let rest for 10 minutes. Carve the breast off off the bone, then slice to serve. Discard bones or reserve for making chicken stock.
While the chicken rests, heat 2 tablespoons oil in a small saucepan over medium heat. Add the onion and garlic and cook, stirring occasionally, until softened, 3 minutes. Stir in the harissa and coriander and cook until very fragrant and dark red, about 2 minutes. Add half the chickpeas and lightly mash them using a fork, the back of a spoon or a potato masher. Stir in the lemon juice and parsley along with the remaining chickpeas, 2 tablespoons oil, and 1/4 cup water. Season with salt and pepper.
Serve the chicken topped with the sauce.

If you don’t have a mortar and pestle, use the bottom edge of a pot or saucepan to crush the coriander seeds.