Boulud serves farm-raised venison loin in his restaurant but tells me he would not change a thing for wild deer, and he uses this recipe for all cuts, from leg to loin. Blending the earthy flavors of chestnuts with the meat, he says, adds a rich fall- and winter-harvest accent. Preparation is key: Start with 3/4 pound of peeled chestnuts, break into smaller pieces, and spread onto a baking sheet. Age the nuts overnight in a warm place. Pulse into 1/4-inch chunks in a food processor; discard smaller pieces and any powder. After marinating your venison for at least 4 hours, pat dry and season with salt and pepper. Beat one large egg in a large bowl. Dust venison with flour; dip it through the egg; and firmly press the chestnut pieces around the meat, covering thoroughly. Cook in a preheated 425-degree oven to your liking, or until the chestnuts are a deep, golden brown.