Debone the chicken the night before.

Use the carcass and trimming to make a stock, adding bay leaf, onion, garlic, celery to the stock pot. Leave the stock in the fridge overnight, and scrapped off the rendered chicken fat for later use.

The next day, take the dried wild mushrooms and soak in water to reconstitute them. Keep the soaking liquor.

Heat one cup of the chicken stock you made the day before with the carcass. When boiling, mix with the cup of dried couscous, add a blob of the chicken fat, mix and leave to rest covered.

Next, sautée the spring onions, yellow pepper, celery, garlic, and mushrooms finely chopped.

In the meantime, soak some maple wood chips in the mushroom soaking liquor, and top up with water.
Add the couscous to the sautéed veg and mushrooms, salt and pepper to taste.

The chicken was then salted on the interior, stuffed, trussed, brushed with the remaining chicken fat, a bit of salt to the exterior, then popped on the kettle BBQ for an hour of smoke and cook till it got to temperature.
I used the kettle bbq as I wanted a higher temperature to crisp the skin.