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).
Time to Blanch. After you have prepped the beans, drop them into the pot of rapidly boiling water. Let them cook for 3 minutes and then drain the green beans in a colander. As an alternative, you can steam the beans for 3 minutes rather than boiling them.