For the chicken, heat a large frying pan over high heat, add the oil and chicken and cook for five minutes until golden. Remove and set aside.
Return the chicken to the pan with the lemon, chicken stock and reduce the heat, cover the pan and simmer for 20 minutes or until the chicken is cooked through.
Lift out the chicken and put on a baking tray. Increase the heat under the sauce, and simmer, uncovered for another 15 minutes to thicken. Place the chicken under a hot grill for five minutes until crisp.
Arrange the chicken on a platter, drizzle with the sauce and sprinkle with oregano. For the salad, gently mix together the feta, parsley, cucumber, tomatoes and olives in a large bowl.
Whisk the olive oil and lemon juice and season with salt and pepper. Toss the dressing with the salad. Serve.