In a saucepan bring broth to a boil. Add carrots, potatoes, and
celery, and simmer for 10 to 15 minutes, or until vegetables are tender.
Transfer vegetables to a bowl, reserving the broth, and add the chicken
to the bowl. In another saucepan, cook the onion in the butter
over medium-low heat, stirring, until softened. Add flour and
cook, stirring, for 2 minutes. Add 3 cups of broth in
a stream, whisking constantly. Bring mixture to a boil, whisking. Add the
thyme and simmer the sauce, stirring occasionally, for 5 minutes.
Stir in nutmeg, parsley, and salt and pepper to taste. Pour the
sauce over the chicken and veggies. Stir the mixture gently, until
it is just combined. Transfer the mixture to a 2-quart baking dish.
Into a bowl, sift together the flour, baking powder, baking soda,
and salt. Add the butter and shortening and blend the mixture
until it resembles meal. Add the cheese and toss. Break egg into
a measuring cup and add buttermilk to it so that the total volume
is 1/2 cup. Beat with a fork. Add to the flour mixture, stirring
until the mixture just forms dough. Gather dough into a ball and,
on a floured surface, pat it out 1/2-inch thick. Cut as many rounds
as possible using a 2-inch fluted biscuit cutter, dipped in flour.
Gather the scraps and pat and cut again.
Arrange the biscuit rounds on the chicken mixture. Beat the egg yolk with
the milk and brush the tops of the biscuits with the wash. Prick
biscuits lightly with a fork.
Bake in the middle of a preheated 450° F. oven for 15 to 25 minutes,
or until biscuits are puffed and golden, and the filling is bubbling.
Adapted from a 1985 Gourmet Magazine favorite, as posted to a cooking forum.
Calories per serving: 540
Fat per serving: 26.3g