Preheat oven to 350°.
Carefully remove the outer papery skin from the garlic heads,
leaving the whole heads intact.
Arrange the garlic heads in a small baking dish so that they fit
comfortably. Dot with the butter, thyme, pepper, and coarse salt.
Pour the chicken broth into the dish.
Cover dish tightly with aluminum foil and bake, basting frequently,
for 1 hour. Uncover and bake 15 minutes longer.