Pour boiling water over tree ears; let stand for 15 minutes.
Peel cucumbers, cut in half lengthwise, scrape out seeds. Slice into thin half-moons.
When mushrooms are soft, drain, rinse and dry. (Slice 'em if they're too big. ~Wood ears will quadruple in size when soaked.)
Combine with remaining ingredients. Let stand for 15 minutes then toss again before serving.
NOTE: (Wood ears can be found in Chinese markets. After soaking they have little taste but lots of crunch. They're there for the texture. I can't think of anything to substitute (maybe raw carrots or water chestnuts) except for dried duck web or jellyfish and you're much more likely to find wood ears than those items. Be sure to use the dark, cooked, Asian sesame oil rather than the light stuff in health food stores. I'd make this before the ribs and chill it well while doing the rest.)