Just take your favourite vegetables – as always: everything is allowed as long as you like it, add salt and mix it.
The relation from vegetables to salt should be 7:1. Hence, if you have 700 g vegetables add 100 g salt.

For getting a typical German vegetable stock I usually use

• 1 Onion
• 2 Carrots
• 200 g Celery
• 1 leek
• 1 bunch of Parsley
• 10 bay leaves
• salt (preferably rough sea salt)

ingredients

If you have a strong mixer, let everything mixed until you have a paste for a vegan vegetable stock.
If not – no problem. Just rasp everything, mix it with the salt and you are also already done.

You can now dehydrate everything to have a real powder but usually I refer from that.
I put everything in glasses, keep it in the fridge and use it whenever needed. I used it to flavour my dishes, to create a fast vegetable soup or spread it over my bread and butter.

finished vegan vegetable stock

For getting the real vegetable soup I just mix one soup spoon with 250 ml hot water.
In case you have a recipe with powder just take the double amount as given.