Remove the pulp from the preserved lemon and add it to a food processor with the lemon juice, garlic, cumin, paprika, oil, pepper, coriander leaves and roots and process until smooth. Wipe the chicken breasts with damp paper towel to clean, then smear the ½ the marinade over each of the breasts. Set aside to marinate in the fridge for 1 - 2 hours.
Preheat BBQ grill.
Cook on the BBQ for approx 7 minutes each side turning once. Serve with the remaining marinade.
Note: Preserved lemons are available from most good delis. They are easy to make if you have excess lemons, just search The Food Coach recipe database.