Here is an idea. Why not reuse the plastic bags that your frozen vegetables come in? After eating the vegetables, simply cut one end off the bag with a pair of scissors. Then rinse out the bag and you’re good to go. The bags can also be washed out with soap and water and used again. Eventually, you will recycle the bag.
You will need some way to hold the bag closed. I have these clips (see photo) but paperclips will work too.
Reduce the amount of plastic you use by reusing something you already have. Works well too!