Prepare the marinade for chicken shawarma by combining the spices, salt, lemon juice, garlic paste and olive oil in a large bowl.
Cut the chicken breasts into bite-sized pieces and add them to the marinade. Mix well, cover the bowl and refrigerate.
Remove the marinated chicken from the refrigerator about 30 minutes before you are ready to grill and thread the chicken pieces onto skewers.
Prepare your charcoal or gas grill. If you're using a gas grill, preheat it to medium-high heat, and brush the grill with oil.
Grill the chicken kebabs on a hot grill for about 4 to 5 minutes. Rotate kebabs and grill for another 3 to 4 minutes until golden and cooked through. *Cooking time will vary depending on the thickness of the pieces of chicken and the grilling temperature.