What would soup be without lentils? Non-lentil soup, that's what. Probably potato, or mushroom, or fish, or any number of other soups. It's a lengthy question to answer in full, actually. But let's not think about that now - this one's got lentils aplenty, and can be made up in a big batch to freeze in snack-sized portions.

250g red lentils
1 tblsp vegetable oil
A large onion, finely chopped
A garlic clove, finely chopped
A celery stick, finely chopped
200g tinned, chopped tomatoes
Half a small, green chilli, deseeded and finely chopped
1/2 tsp paprika
1/2 tsp harissa paste
1/2 tsp cumin
600ml vegetable stock or water
Salt and pepper
1 tblsp chopped coriander (to garnish)

Put the lentils in a bowl of water.
Heat oil, fry onions, garlic and celery til soft.
Add lentils and tomatoes to the pan.
Add chilli, paprika, harissa paste, cumin, stock, salt and pepper.
Cover and simmer 30-40 minutes, or until lentils are soft. You might need to add water periodically.

Not On Fire has another great lentil soup recipe.