In a bowl, whisk 1/4 cup of the oil, lemon juice, zest, garlic and oregano. Fold in the artichokes, olives and feta; season the sauce with salt and pepper.
Season the chicken with salt and pepper. In an ovenproof skillet, heat the remaining 1 tablespoon of oil.
Add the chicken, skinned side down, and cook over moderately high heat until browned, 3 minutes; turn and transfer the skillet to the oven. Roast the chicken for 10 minutes, until white throughout.
Transfer the chicken to plates and spoon the sauce on top.