A decade ago, Hell's Kitchen was the foremost destination for Thai food in the city, with such prominent players as Larb Ubol and Pam Real Thai Food in the neighborhood.At the time I walked the length of 9th Avenue from 53rd Street down to 36th Street, and counted 38 Thai restaurants on the avenue and side streets, sometimes ganged up in threes and fours on a single block, with multiple branches of some like Wondee Siam.