Smorgasburg Los Angeles runs every Sunday at Row DTLA in the Arts District — 80 to 100 food vendors spread across an open lot with downtown skyline views. It started in Brooklyn and landed in LA in 2016. The LA version skews toward vendors you have never heard of who are testing their first concept: smash burgers from a popup that has been selling out of a parking lot in Koreatown, birria ramen from a chef who used to run a Michelin kitchen, cheese bao from someone who will have a brick-and-mortar within two years. The market is how those businesses get their first real crowd. The crowd itself is …