Let your fire or barbecue burn down to embers.
Heat a drizzle of olive oil in a pan and add the chopped garlic, celery, onions, potatoes and carrot. Add half the thyme. Sweat the vegetables until they are soft, about 10 minutes.
Chop the chicken livers. Mix together with the drippings and wine. Use this mixture to stuff each of the chickens.
Stitch up the opening in the chickens with (soaked) wooden toothpicks and rub them with olive oil, salt and pepper.
Sprinkle the chickens with the rest of the thyme, and wrap each one in five layers of foil.
Bury the foil-wrapped chickens in the embers and cook for 45 minutes. Remove from the embers with tongs and blow off the ash.
Once cooked, snip open the foil carefully. Pour any juices in to a bowl and put to one side.
Cut each chicken in half with poultry shears and scoop out the stuffing.
Serve the chickens on top of the stuffing and pour over the juices. Drizzle some olive oil and thyme around the outside for effect.