Clean the celeriac, cut into large chunks and cook them in the stock with the cream until tender. Puree the cooked celeriac into a smooth paste in a blender with a little of cooking liquid. Season with salt and pepper. Mix half the celeriac cream with the black garlic puree and the other half with 4 g of the roasted garlic puree.
Season with chicken with the organic garlic puree, salt and pepper and fry on all sides in hot oil. Add the butter and roast the chicken until done in the oven at 160˚C. Baste regularly.
Peel the potatoes and chop into pieces. Cut the bacon into strips and chop the onion into half-rings. Add the onion and the bacon to the chicken and continue to baste. Clean the leek and cut it into coarse rings. Cut the carrots into ribbons. Add the leek and the carrot to the chicken and allow everything to cook while continue to baste.
Pipe both purees, alternating the flavours, into tiny swirls on the plate and spread them out with a pallet knife. Carve the chicken and serve it with the vegetable garnish.