Put the carrots, celery, onion and garlic together in a pan over medium heat with the lid askew. Cook for 10 minutes until the carrots have softened and the onion is lightly golden.

Add the stock to a pot with 1.8 litres (about half a gallon) of boiling water. Stir until the stock is dissolved, then add lentils, tomatoes, ginger, and chilli. Add the carrot-celery-onion mix, along with the pan juices. Stir the soup and bring to the boil.

Once the soup has reached boiling point, reduce the heat to a simmer. Put the lid on and leave it for 10 minutes, or until the lentils are cooked. Add the spinach and cook for 30 seconds.

Season well with salt and pepper. The soup can be served nice and chunky, as is, or use a hand blender to pulse until smooth. Serve with a dollop of natural yoghurt if you'd like.