I have always been a big fan of shallow poly boxes for that.

Cold cuts are sometimes packaged in a nice plastic tray, Chinese take out food, shallow Tupperware containers, all make fine ponds that are washable.

I am a "gummy bear" addict, so I get the ones in plastic bowls, that way I am buying a cheap bowl with free gummy bears, or gummy bears with a free bowl, either way it's a bargain.