Rinse the red lentils under running water.
Cut the peppers, carrot and onion into tiny cubes, then chop the garlic and rosemary leaves.
Heat the oil in a large pot and gently sauté the onion, pepper and carrot for about 5 minutes, then add the garlic, paprika, rosemary, marjoram, tomato purée and chilli flakes. Sir for a minute to coat everything, then add the lentils and plenty of water to cover well.
Add the stock cube and bring to the boil. Cook for 20-25 minutes or until the veggies are tender.
Using a hand-held blender, whiz the soup until you get a textured, rustic finish.
Add the drained chickpeas and more water if necessary.
Heat it up, then serve. You can add some chopped herbs, if liked - parsley, basil, coriander, mint would go well with the soup.