Cut each chicken breast into small bite-size pieces.
Combine yogurt, curry, lemon juice and salt. Mix, and marinate the chicken
in about three quarters of this mixture for one hour or longer. Save the other
one quarter of the marinade for basting the chicken as it cooks. A health note
here: DO NOT use the same marinade in which you marinate the chicken for basting.
Thread chicken on skewers, with onions and tomatoes in between every two
or so chicken pieces.
Grill over charcoal or in oven broiler, turning until chicken is cooked
(about 10 minutes) and basting with marinade.