150g Soup Mix (Tesco brand: 55% pearl barley, 18% yellow split peas, 9% green split peas, 9% marrowfat peas, 9% red split lentils)
1 celery plant (6-8 stalks approx, I had to remove some grubby bits because the one I used was getting old)
2 medium carrots
Half a large onion
1 teaspoon of salt
Soak soup mix overnight (I soaked them for 10 hours approx) in a large saucepan with the lid on.
Drain the soup mix in a sieve and rinse thoroughly with cold water, then return to the saucepan.
Fill the kettle and switch it on.
Finely chop all of the vegetables and add them to the saucepan.
Add the teaspoon of salt.
When the kettle is boiled, cover the contents of the saucepan with boiling water. I filled it until the water was 2-3cm above the vegetables. Stir thoroughly, taking care to unstick any lentils from base of pan.
Bring to the boil and simmer for 30 minutes, stirring occasionally.