These sheet-pan chicken thighs gain gorgeous color from a harissa-yogurt marinade, which also keeps the meat juicy during the roasting process The thighs only need 15 minutes in the marinade, but you can leave them for up to 24 hours in the fridge For weeknights, heat the oven, place the chicken in the marinade, then wash and cut the sweet potato and kale, so the prep work is done and the oven hot by the time the chicken is done marinating