1. Heat the oil in a non-stick pan on the hob over medium heat. Add the leeks and cook for a few minutes until they soften.
2. Add the chopped carrots, mushrooms and garlic and continue to cook for a few minutes, stirring to keep from sticking.
3. Add the fresh herbs, lentils, tomatoes, Beetroot & Red Onion Chutney, chilli flakes, vegetable stock, and red wine. Stir well to combine and bring up to the boil before reducing to a simmer and cooking on for a further 20 minutes.
4. For the topping, bring a large saucepan of water to the boil (there’s no need to add salt). Add the sweet potatoes and sweet potatoes and boil for 10 minutes. Add the cauliflower to the pot and continue to cook until all the vegetables are tender. Drain and return to the pan. Allow to steam for a couple of minutes before adding the butter.
5. Season with a generous pinch of salt and black pepper before mashing to a smooth consistency. Finally, mix through the grated Parmesan and stir through the mix.
6. Season the vegetable mix with salt and pepper to taste before transferring to an ovenproof dish.
7. Carefully spread the potato mixture over the top, using a fork to create peaks.
8. Place in a pre-heated oven 200c (180c fan) for 25 minutes, or until you can see the mixture bubbling and the topping is a golden brown colour.