Put the bread in a mixing bowl. Pour the milk over the bread and let stand for 2 minutes to soften. Press out and discard the milk.
With a fork, work in the sausage meat, garlic, and shallots, breaking up any large lumps of meat. Add the beaten egg, parsley, chives, salt, pepper, and nutmeg; blend well. Chill the stuffing to firm it up, about 30 minutes.