Ryan Serhant, New York City’s self-described “#1 Broker,” is on a roll. Since we left him at the end of last year’s season, the star of the hit reality TV show Million Dollar Listing New Yorkgot married on a Greek island. He landed a new show, Sell It Like Serhant, in which Bravo promises he will transform floundering brokers into selling sharks. And he opened a new Nest Seekers office in Brooklyn’s Bedford-Stuyvesant neighborhood, planting his flag in one of the hottest housing markets in the country.