Chris McKenzie, better known as “Mac,” has been in the food business for a long time, but he’s recently started a new venture in Dogtown —Mac’s Local Buys Market (1221 Tamm Avenue). The shop specializes in local food made in small batches, from fresh-baked bread to dry-aged, grass-fed beef.McKenzie, who got his start in the food business with the CSA Mac's Local Buys, is now the chef at Mac’s Local Eats, a well-reviewed burger joint inside Tamm Avenue Bar.…