Heat the oil in a pan, add the onion, carrot and celery, and gently cook for 10-15 mins until soft. Add the garlic, cook for a few minutes, then stir in the lentils and cornflour.

Add the tomatoes plus a canful of water, the mushroom ketchup, oregano, stock powder and some seasoning. Simmer for 15 mins, stirring occasionally.

Meanwhile, cook the cauliflower in a pan of boiling water for 10 mins or until tender. Drain, then purée with the soya milk, dijon mustard and nutritional yeast using a hand blender or food processor. Season well and add the nutmeg.

Heat the oven to 180C/160C fan/gas 4. Spread a third of the lentil mixture over the base of a ceramic baking dish, about 20 x 30cm. Cover with a single layer of lasagne, snapping the sheets to fit. Add another third of the lentil mixture, then spread a third of the cauliflower purée on top, followed by a layer of pasta. Top with the last third of lentils and lasagne, followed by the remaining purée.

Cover loosely with foil and bake for 35-45 mins, removing the foil for the final 10 mins of cooking.