So I decided to rethink how I stored them. I recycled three 2-liter plastic milk bottles for the corn, peas and frozen chopped onions.

As you can see, they fit perfectly into the space:

Here is an empty bottle:

To fill the bottle with veg I use the little funnel that came with our dishwasher (for filling the dishwasher salt container) - it's perfect:

But if you don't have one, the cut-off top of a pop bottle will do the trick:

Voila - filled with a bag of corn. You want to squish the bag well before opening it, to ensure that all clumps of corn are broken down - that way they don't jam up in the funnel:
