Preheat oven to 350°F.
In a small bowl combine the zest, pepper, salt, garlic powder and cornstarch.
Rub the spice mixture into the legs on all sides.
Heat the olive oil in a large cast iron skillet until hot but not smoking.
Add the chicken, searing on all sides until browned. Pour the orange juice and beer over the chicken.
Transfer pan to the oven, cooking until the chicken is cooked through, about 25 minutes.