Simply wash and reuse those plastic trays from frozen meals.
If you are so environmentally aware and/or thrifty that you never buy frozen meals, I bet you know somebody who does and could ask that person to save some of the plates for you.
Personally, although I try to plan home-cooked meals that we can make in large quantities so we’ll have plenty of leftovers that I can take for my lunch at work–in durable, washable containers, in a cloth lunch bag, with a real fork and a cloth napkin–sometimes I’m not prepared for every single day. Although I also try to do my part to support our local economy by eating in restaurants, I can’t afford to do a whole lot of that. So I fill in the gaps with frozen meals. I only buy all-natural vegetarian meals, and I recycle the cardboard box and plastic plate–or, as much as possible, I reuse the plates.
I have a six-year-old son who likes to eat snacks. He also likes to have meals with components (like beans, guacamole, diced tomato, and chips) served with each component in a separate dish. We often use the 1-cup tempered-glass bowls with plastic lids, so that if he doesn’t finish something we can pop on the lid and save it for later. But there’s a limit to how many of those we can have: They’re heavy and don’t stack well–taking up a lot of space in the cabinet–and they’re expensive to buy, although they do last for years.
Therefore, when serving him (or myself) foods that are not hot or greasy, I often use the plates I saved from frozen meals. They’re smaller than our real plates, so more of them fit on a placemat. Some of them have little compartments, ideal for foods like veggies and dip. They don’t shatter if dropped; although they can crack, making sharp edges, at least it’s no loss if this happens because we were getting free use out of them anyway and there are always more coming! They’re lightweight, but the raised edges help prevent snacks from scattering at the slightest bump. They wash pretty easily–they can even go in the dishwasher–but if one gets forgotten until ketchup is welded onto it, I can throw it away. I also get rid of them (via recycling) once they are the least bit scratched, bubbled, or otherwise worn-looking. I consider them semi-disposable.
Why don’t I use them for hot or greasy foods? Well, both heat and grease cause chemicals from plastic to bind to food, and I want to avoid eating those chemicals as much as I can (conveniently…) even if they aren’t yet known to be health hazards. I figure I get more than enough exposure to them from eating the frozen food microwaved in the plastic dish! Each subsequent time that dish is used, the plastic gets a little older and more worn. So we use them only for foods like raw fruits and veggies, trail mix, chips and salsa, cheese and crackers, etc.
Reusing plastic frozen-food plates and then recycling them saves money that we would otherwise have spent on more real plates, saves cabinet space, and reduces the wastefulness of eating frozen meals. It works for me!