Dry chicken and place 2 truffles inside. Slice remaining truffle very thinly. Carefully slide slices under the skin of the chicken. Cover the bird with waxed paper and place in the refrigerator for 24 hours.
The next day, preheat oven to 350 degrees F. Sprinkle Madeira over bread pieces. Add thyme, salt, pepper, and bread to the pate. Mix until smooth. Remove the truffles from the cavity of the chicken. Slice them thinly and add to the pate mixture. Stuff the bird with the combined mixture. Pin and truss the bird, securing the flesh with poultry pins and the wings and legs with string. Season breast with salt and pepper. Lay bacon over the bird to keep it moist.
Roast bird on baking dish for 1 hour. Remove bacon and reserve for garnish. Cook bird for 15 minutes more. Remove string, transfer to serving platter and arrange garnish around it.