Serves 4-6

Tinned tomatoes are one of the most indispensable and healthy convenience veg. Like so many perfectly good basics, though, they're often messed around with and come with flavourings like garlic and various herbs. I prefer to buy the plain chopped ones, and then add my own fresh flavours depending on what I'm cooking.

2tbsp olive oil
1 onion, peeled and roughly chopped
1 small dried chilli
1tsp cumin seeds
160g red lentils
2tsp white wine vinegar
400g can of chopped tomatoes
2tsp tomato purée
Salt and pepper
2 litres vegetable stock - use good-quality stock cubes or powder
1 bay leaf

Gently cook the onion, chilli and cumin in olive oil for 3-4 minutes until soft. Add the lentils, vinegar, chopped tomatoes, tomato purée and stock, season, add the bay leaf and bring to the boil. Simmer for 40 minutes stirring every so often, until the soup is a rich and thick consistency. If it looks too thick, add a little more stock and re-season if necessary.