Heat olive oil in a dutch oven, place the sausages in and lightly brown them. Do this in batches.
Remove the sausages, allow them to cool, and then cut them into bite-sized pieces.
Add finely diced onion and celery to the pot and cook until tender. Add the sliced mushrooms and continue cooking until the mushrooms are soft.
Remove the pot from the heat. Then add beef stock (or both), Worcestershire sauce, tarragon, coriander, frozen mixed vegetables, barley, chopped sausages, butternut pumpkin, spinach and bay leaves. Stir well.
Cover and place in the oven to cook for 1 and ½ hours or until cooked.