[throwaway55554]

You probably know this, but for others, onion (and other veggies) freeze well. I'll usually chop up most of the bag and put all of it in freezer bags and freeze laying flat (breaking them up during the freezing process to they stay loose). It is then easy to pour out half cup or whatever the recipe calls for.

[JoeAltmaier]

Yeah we have a freezer for garden produce - tomatoes, peppers, beans etc. All portioned out in sizes useful for cooking.