Hi everyone, I ordered a two-tier bento box online a couple of days ago (it hasn't arrived yet), and I'd like to know if it's possible to use just one tier, and leave the other one at home? This is the box: http://www.bentoshop.de/Bento-Boxen-fuer-Erwachsene/Bento-Box-Blossom::107.html Thank you! - Katie