take some water challah [old is better] or french bread & cut it up into cubes ... spray a little olive oil & spices & toast a bit in the oven ...
next - saute onions, garlic, celery [all diced into small pieces] in a fry pan with olive oil & black pepper and garlic powder ...
add the breadcrumbs you just made to the pan ... and some chicken juices from the chicken pan drippings [assuming you started to cook it & you should start to cook it before stuffing]
then when all is nice and flavourful - stuff the half-baked chicken with the mixture & continue baking chicken & basting chicken every so often
