Heat the oil in the base of a tagine or a large, heavy-based saucepan over a medium heat, stir in the caraway seeds, garlic and chilli and cook for 1–2 minutes to let the flavours mingle. Add the carrots and celery, stir to coat well and cook for a further 1–2 minutes, then add the lentils.
Pour in the stock and bring to the boil, then reduce the heat, cover and cook gently for 25–30 minutes until the lentils are tender but not mushy. Season to taste with salt and pepper, then stir in the parsley. Serve as a side dish with wedges of lemon to squeeze over it.