Eeek, I'm surprised no one has suggested this yet - my eyes actually got wide when I read your question and excited about what wonderful soups you could make.
Empty out a large juice container (like a big Tropicana OJ bottle, or a similarly large plastic juice container). Put the mush in there and refrigerate or freeze (depending on how much you put in there). Add new mush to the bottle each time you have some.
When you have the desired amount: make some soup.
Cook the vegetable mush at a low to medium heat in a stock pot, adding 1 cup of water for every 2 cups of mush, add seasonings (these can be flexible depending on your personal tastes...but certainly add salt).
The thickness of the stock is dependent on what type of soup you'd want to make (and soup is so easy to make and so yummy). Creamier soup = thicker stock (if you think it's too watery, add cream of tartar until it reaches desired consistency). Thinner broth soup = add water until desired consistency is reached.
Cook for at least one hour and skim/filter off any gunk that has risen to the top or any floating pieces of stuff you may have added (such as veggies, onions, or bones/meat if you wanted to turn it into a chicken broth or turkey broth, etc). Note: if you are turning it into a meat broth and have added meat/bones to the stock, you'll have to cook it much longer. Veggie broth only requires about an hour because there is already so much water in the veggies, it evaporates quicker.
Once you have your stock/broth all filtered and cooked - make your soup (which can be as simple as adding some freshly steamed veggies, or steamed tofu, or boiled chicken and veggies, or boiled/diced potatoes and oh..you get the idea). Any leftover stock can be put back in the previously mentioned plastic container and stuck in your freezer. It will keep for a LONG time (months and months) and you can thaw it out whenever you need broth or a base for gravy. There are tons of recipes for homemade stock online as well. It may take a lot more effort than store bought stock, but the soups it makes are noticeably more flavorful and delicious.
Or, you can get a saucepan - toss a bit of butter on there and some thinly diced onions, then the veggie mush, a protein source of your choice (chicken, beef, tofu, etc), some rosemary, thyme, salt, pepper, and maybe a smidge of paprika or cayenne if you want some spice - cook and spread over rice. You could also add some curry to the mix if you wanted to turn it into a vegetable curry sauce.
Wordy - I know. I get excited about cooking.
"There is nothing more frightening than ignorance in action." -X