It's delicious. The chestnuts you brown in butter, then braise in chicken stock in a 400º oven (which looks like this):
Blanch some pearl onions quickly in salted water for 2 minutes, and finish cooking in butter, sugar and a little salt. Then combine this with a julienne of fennel and shallots, cook until soft, add walnuts, then add this mixture to the cooked chestnut, along with a tablespoon or so of chicken juices, if you have any. Garnish with the fronds.
The brochettes are also from that book. Simple and tasty.