Two weeks ago the big news was the opening of Husk Nashville, the sister restaurant to Sean Brock’s Charleston, S.C., shrine to Southern ingredients and folkways. Dinner reservations got snapped up. This week Husk started serving lunch, providing more chances for people to try the cuisine dreamed up by Brock and his chef de cuisine in Nashville, Morgan McGlone. In addition, this weekend Husk is adding Saturday and Sunday brunch.