Keep a container in the freezer for leftover vegetables. Periodically use to make soup.
Add to the vegetables a can of tomatoes (I use the Italian seasoned ones), water, a stock cube, and dried beans for protein (soak beans prior to adding). Cook either on the stove or in a crock pot. If you don't use Italian seasoned tomatoes, add seasoning. Thyme, rosemary, bay leaf, salt and pepper are usually good additions. Taste first, before adding salt as the stock cube contains sodium.
In the summer, after cooking, put the soup mixture in the blender and refrigerate. Drink cold.