For the quails stuffed with goose liver on fennel-maroni vegetables, preheat the oven to 200 °C top and bottom heat.
Wash and dry the quails. Season inside and out with salt and pepper. Cut the foie gras into fine cubes and purée finely with whipped cream, port wine and lemon zest.
Fold in the bread croutons, rosemary and thyme and stuff the mixture into the quails. Wrap each quail with two slices of bacon and secure it with kitchen twine. Place the quails in a roasting pan, brush with butter, season with salt and pepper and roast in a preheated oven for about 35 minutes until golden brown, brushing with the drippings in between.
While the quails are roasting, prepare the vegetables. Clean the fennel, cutting off the fennel greens and reserving them. Wash the fennel and cut into small pieces.
Rinse the fennel greens and pluck into pieces or chop coarsely. Cut large chestnuts in half if necessary, leave smaller ones whole. Peel and finely chop the onion. Sauté in half of the butter, add the fennel and steam, salt, pepper, pour in wine and half of the vegetable stock and steam covered for about 10 minutes.
Sauté the chestnuts in the remaining butter, sprinkle with sugar and caramelize. Season with salt and pepper, pour in the remaining vegetable stock and let the liquid boil down almost completely.
To serve, arrange the fennel vegetables on preheated plates, place one quail on each plate and