Mouth-watering tours are offered by Absolute Asia , with a private 11-day trip for $ 3,700 to $ 4,570 a person , double occupancy , excluding international air fare , ( 800 ) 736-8187 , www.absoluteasia.com , and Artisans of Leisure , with a private 16-day food tour of Vietnam , Thailand and Singapore for $ 6,880 a person , double occupancy , without air fare ; ( 800 ) 214-8144 ; www.artisansofleisure.com .