Place chicken breasts on a large plate and rub with oil and paprika to coat.
Heat a large non-stick frying pan over medium heat. Add chicken. Cook about 5 minutes on each side, or until browned and cooked through. Transfer to a plate. Cover with foil and rest for 5 minutes.
Meanwhile, to make dressing, combine all ingredients in screw-top jar, season with pepper and shake well.
Thinly slice chicken. Arrange chicken on a platter with corn, lettuce, avocado, tomatoes, cucumber, eggs and onion. Drizzle over dressing to serve.