If you're like me, you don't always use the whole large onion in the same recipe. So what to do?
You could put it in a ziploc bag and place it back in the fridge, where it may get lost and turn into a creepy, gooey, bluish mass . . . Tupperware made these cool containers specifically for this purpose that my mom has. It hangs below the shelf of your fridge, where you can see it!
I don't have room in my tiny kitchen for extra containers (appliances, etc) with only one use.
I chose to puree it . . . it is going in soup and I didn't have time to sautee it this morning.
I flipped it over, wiped the rim, placed and lid & ring on top and set it in the fridge for later this week.