Dressed in a harvest-gold, damask-patterned sherwani – a coat-like lengthy garment common in India – President of the India Association of Long Island, Lalit Aery, zipped between tables as he greeted the 300 people dropping in their banquet to celebrate Holi.

As soon as you enter the restaurant, you are greeted by the big, warm smile of Mr. Kulwant Wadhwa—the owner of Curry Club. The entrance is adorned with several Hindu idols and has the ambience of...