A discussion of what frozen vegetables are similar to fresh, and for which purposes, might be useful. One person probably doesn't want a whole cauliflower, maybe not even half of one: but she can grab a half-cup from a package of frozen cauliflower in the freezer and steam it or put into a stir-fry. (Cauliflower comes to mind because that's one my girlfriend keeps in her freezer.)

I'm thinking of things where it's more or less interchangeable, not something like dried mushrooms, which have to be treated differently from fresh. I realize that this is somewhat subjective: people disagree about frozen bell peppers, for example.