In a mason jar or bowl mix together the olive oil, red wine vinegar, dijon mustard, garlic, oregano, basil, onion powder, salt, and pepper.
Place the chicken in a container and pour half of the marinade over the chicken. Cover the chicken and refrigerate for an hour or overnight.
Place the vegetables in another bowl and pour the rest of the marinade over top. Cover the vegetables and refrigerate for an hour or overnight.
Preheat oven to 375 degrees.
Place chicken and vegetables on a sheet pan coated with cooking spray. Bake for 30 minutes or until chicken is no longer pink and juices run clear. Internal temperature should be 165 degrees.
Serve hot or cold. Sprinkle 1 tablespoon feta cheese and 2 olives on each serving.