Heat the oil in a large saucepan over a medium heat. Add the onion, garlic, cumin, paprika, chilli flakes, pepper and carrot and cook for about 5 minutes until softened.
Add in the tinned tomatoes, tomato puree, hot stock, Henderson's Relish (or Worcestershire Sauce) and red lentils. Stir well.
Simmer on a medium heat, with the lid on, for 30-40 minutes until the lentils are soft and the soup is thick.
Use a food processor or hand blender to make the soup smooth, then serve.
Did you make this recipe? Click here to let us know how it went and give it a ⭐️ rating! Your feedback helps us to make more recipes you really want.