Early generations of short wave radios had large flat tuning dials requiring spreading all five fingers and placing them on the circumference of the dial in order to gently turn the dial right or left to tune in a distant location (Rangoon). Spatially, the gesture resembles that of palming a woman's ample breast.
Two guys are sitting in a bar, in walks a woman with large breasts, one guy turns to the other, winks and says 'Come in Rangoon.'
The act of busting a mad nut in a fruit rollup, then wrapping it in a Crab-Rangoon manner and presenting it to your female companion for the most delightful and delicious consumption.