Most Dallasites already know what aroma they'll encounter when they order food flavored with "kah" or "kaffir," because Thai food has become a neighborhood option, like Mexican food or Vietnamese. (If you don't know, "kah" is similar to ginger root--it's also called "laos" or "galangal." The leaves of the "Kaffir" lime tree impart a citrusy smell.) But, in May, you'll have a rare chance to expand your Thai taste buds when chefs from Bangkok's Dusit Thani Hotel move into the Melrose to take over the kitchen for two weeks. May 7 through May 15, a Royal Thai prix fixe dinner ($29.95) will be available in the evenings. Thai food will be served a la carte at lunch, and the Melrose is hosting a number of other special events featuring centuries-old Thai cuisine as it is prepared in Dusit Thani's Benjarong Restaurant. Not to mention demonstrations of Thai fruit carving, Thai dance and music, Thai arts and crafts, and Thai cooking classes.