Preheat the oven to 425 degrees F.
Place the chicken thighs in an 8-by-8-inch baking dish. Whisk
together the olive oil
, chili powder, garlic, orange zest
and orange juice
in a small bowl. Pour this mixture over the chicken thighs
and leave to marinate at room temperature for 20 minutes.
Transfer the baking dish
to the oven and roast
until the chicken is cooked through, about 20 minutes.