When making most soups I use a basic formula of sliced potato, chopped onion and chosen veg, then Oxo vegetable stock, cornflour, water and black pepper. This formula works for most of my soups. Celery soup is very easy to make and really good tasting too, and from a budget point of view it's relatively cheap as well. Celery is also low calorie, full of anti-oxidants and a good source of fibre. It has also been used in Chinese medicine for centuries.as an anti-inflammatory so should definitely help with Arthritic conditions too. I always serve the soups with crusty bread or sliced wholemeal bread.
Here is the Recipe
