Elizabeth Hill began offering weekend food tours of eateries in West Marin after taking a drive last spring with some friends from culinary school. Through her new business, West Marin Food and Farm Tours, Ms. Hill ferries food lovers to Marin Sun Farms, Cowgirl Creamery, Point Reyes Vineyards, Table Top Farm andother destinations as part of a half-day excursion that offers a glimpse into what she describes as a “hotbed of the sustainable food movement.”