Step 1

Heat the 1 tbsp oil in a large saucepan and gently fry the 1 small red onion, 2 garlic cloves, and 1 tsp ground cumin, 1 tsp ground coriander and 1 tsp ground turmeric on a low-medium heat for about 5 minutes; add a drop of water if they start to stick.

Step 2

Add 1 x 400g tin chopped tomatoes, 500ml vegetable stock, 1 x 400g tin green lentils and 1 small carrot to the pan. Bring to the boil then turn down the heat and simmer for 10 minutes, until everything has softened. Taste and season with salt and pepper accordingly.

Step 3

Put the soup in a blender and pulse a few times, or use a stick blender. Aim for a fairly thick, coarse-textured soup.

Step 4

Stir in the handful of chopped watercress leaves and squeeze in the lemon juice. Heat back up to piping hot before serving.