Melt the oil in a large saucepan. Add the onion and garlic, cook until soft, then add the spices and stir for 2 more minutes.
Add the carrots and saute until tender over a medium heat.
Add the vegetable stock, tinned tomatoes and lentils, bring to the boil then reduce to a simmer and cook for 20 minutes.
Add a squeeze of lemon juice and adjust seasoning to taste.
Use an immersion blender or food processor to blend until smooth. Place the soup back on the heat and ensure it has warmed through.
Garnish with coriander and serve immediately.