Blend the lemon juice, basil, garlic, salt, pepper, and cayenne pepper to make the marinade.
Plsce the chicken breasts in a deep pan or bowl and pour the marinade over it making sure that all of the chicken is covered. Put a lid or cover on the container and let it sit in the refridgerator over night. In the morning turn the chicken over or move the breasts around. Let the chicken marinate for approximately 4 more hours.
Preheat your oven to 375 degrees F (190 degrees celsius). Drain the liquid (but do not discard it) from the chicken and bake it in the preheated oven for 15 minutes. This is not to cook the chicken but only to brown it.
Next pour the marinade back over the browned chicken and cover the pan tightly with aluminum foil (Be careful not to burn your fingers!). Put the chicken and marinade back into the oven and reduce the heat to 250 degrees F (120 degrees celsius).
Baste the chicken with the marinade sauce every hour for three hours. After 4 hours add the potato slices to the pan and baste the chicken and potatoes well. Recover with the aluminum foil and bake for one more hour.
At this point you may blend all of the ingredient listed for the thoom. This will be used as a condiment for the chicken and potatoes.
Traditionally, this Lebanese Garlic Lemon Chicken is served with warm pita bread.
