Heat a splash of olive oil in a large saucepan and fry the onions, pepper and garlic gently for 5 minutes until softened.
Add the curry powder for a minute then stir in the tomato purée, for another minute. Pour in the coconut milk and add the remaining vegetables, lentils and stock. Bring to a simmer, cover with a lid and cook for 25–30 minutes until the vegetables and lentils are soft. Season to taste.
At this stage, you can either serve the soup chunky, or use a stick blender to blend until smooth (or somewhere in between the two).