How to Make It
Heat oven to 400° F.
Place the cauliflower in a single layer on the bottom of a large roasting pan. Drizzle with 2 tablespoons of the oil, ½ teaspoon salt, and ¼ teaspoon pepper.
Place the chicken on top and drizzle with 1 tablespoon of the oil, ½ teaspoon salt, and ¼ teaspoon pepper. Roast until an instant-read thermometer inserted in the thickest part of a breast and thigh (avoiding the bone) registers 165° F, 50 minutes to 1 hour, 10 minutes.
Transfer the cauliflower to a serving dish.
Let the chicken rest for 10 minutes before carving on a cutting board.
Transfer the chicken to the serving dish with the cauliflower.
Pour 3 tablespoons of the pan juices into a small bowl. (If you don’t have enough pan juices, make up the difference with water; first spoon water into the roasting pan and scrape up the browned bits.)
Add the parsley, lemon juice, capers, and the remaining 3 tablespoons of oil and mix to combine.
Serve the sauce over the chicken and cauliflower.