Wood will expand and contract across the grain, and a wide panel made of solid wood could change width by a half of an inch, warping the door frame. By allowing the wood panel to float, it can expand and contract without damaging the door.
Put trimmed and cleaned green beans in the steamer basket, set over the boiling water, cover, and steam until tender to the bite, 3 to 5 minutes (depending, again, on how crisp or tender you like your green beans).
Over a pot of boiling water, steam beans for 15-20 minutes (until just tender with a littlebite to them; Also, to steam I use a covered colander over a Dutch oven filled 1/4th full with water) Remove steamed beans and turn into a serving bowl. Add all of the rest of the ingredients, seasoning to taste.