Restaurants searching for farm-fresh ingredients often grow some produce of their own — a patch of herbs, or maybe some tomatoes. The folks at the Hermitage Hotel have taken a bigger step. First they cultivated land on the historic Glen Leven estate, where chef Tyler Brown of the hotel’s restaurant, the Capitol Grille, enjoys digging in the dirt to grow heirloom veggies. Then late last year the hotel made a grander move: It bought a 225-acre cattle farm just across the county line in White Bluff, Tenn. Double H Farms, as it’s called, is now up and running — meaning the Capitol Grille’s popular burger, called the Double H Tennessee Stack, is as local as the cow next door.