Heat the oil in a large, heavy-based pan.
Add the onions and cook gently for 5 – 10 mins until softened.
Add the garlic, spices, dried thyme, carrots, celery and peppers and cook for 5 minutes.
Add the tomatoes, stock, courgettes and fresh thyme and cook for 20 - 25 minutes.
Take out the thyme sprigs.
Stir in the lentils and bring back to a simmer.
Serve with wild and white basmati rice, mash or quinoa.