Freeze friendly baked side dishes
Most things baked in a casserole will freeze well ... in part it's because you have a container that's got a relatively low surface to mass ratio, and only exposed to evaporation on one side.

That being said, when you say 'a guilty feeling with the environment', if you're talking about an enviromentalist type perspective, then cooking, freezing, then cooking again is not energy efficient.  (your energy, sure ... but not electricity &amp; gas ... unless it's the trips to the store that you're avoiding).

There are a fair number of cookbooks out there for what's called 'freezer cooking' or 'once a month cooking'.  You  should find a few websites if you search on those terms.  (and we've even had a question about it before).