In a small bowl, stir together the oil, lemon juice, zest, garlic, oregano, mustard, sea salt and black pepper.
Put the chicken into a baking dish in a single layer. Drizzle with the marinade and rub to coat all sides. Let the chicken marinated in the fridge for at least 30 minutes.
When ready to bake, tuck a few fresh lemon slices around the chicken and sprinkle with fresh herbs, if desired. Bake in a preheated 350-degree F oven for about 45 minutes, or until the chicken reaches an internal temperature of 165 degrees F on a meat thermometer.