Heat the oil in a large saucepan, add the onion, celery and carrot and cook gently for about 10 minutes until softened.
Add the garlic, chicken seasoning and thyme and cook for another minute.
Add the stock, pasta, chicken and a good grinding of black pepper. Simmer for about 10 minutes until the pasta is cooked, adding a splash more stock if needed.
Check the seasoning and add salt/pepper/chicken seasoning as needed then serve right away.
Notes
See post above for tips and details.
*You can use any kind of dry pasta shapes or noodles that you like. Here I used pappardelle but a small soup pasta or orzo work really well; or you can even use broken up spaghetti.
**Instead of the seitan chicken, you can use about 50g/2 oz of dried TVP chicken style pieces, soya chunks or soya curls. Rehydrate them in warm water then squeeze them out thoroughly before adding them to the soup along with the pasta.
You can also use shop bought vegan chicken, if it is a ready to eat one it can be added straight to the soup, some others may need to be cooked first, just check the instructions on the packet.