Elaine Low Senior TV WriterFrom TV writers’ rooms to executive offices to on-site productions, there are certain Los Angeles eateries that seem to have a ubiquitous presence at group work lunches across Hollywood: Joan’s on Third, Tender Greens, Sweetgreen.For group-order staple Mendocino Farms, over 50% of its Los Angeles business revolves around the entertainment industry. But once COVID-19 hit the U.S.