1

Heat the oil in a nonstick pan over a medium-high heat and fry the onion and carrots for 5-6 minutes, until softened. Add the garlic and half the sage and cook for 1 minute. Stir in the turkey and tomato purée and cook for 5 minutes. Add the wine, simmer for 1-2 minutes, then stir in the tomatoes and 3 tablespoons water. Season then reduce the heat and simmer, covered, for 15 minutes, adding a splash of water if the mixture gets too thick.

2

In a bowl, combine the ricotta, egg and remaining sage, then season. Put the spinach in a large heatproof bowl and pour over boiling water from the kettle. Let stand for 1 minute, then drain and set aside to cool. Squeeze out any excess liquid, then chop.

3

Preheat the oven to 200°C, fan 180°C, gas mark 6. Assemble the lasagne: spread a thin layer of the turkey sauce over the base of a 25cm square baking dish. Cover with one-third of the sweet potato slices, making sure they overlap a little. Spread half the remaining turkey sauce over the potatoes, then cover with another third of sweet potatoes. Top with the spinach, then spoon the ricotta mixture over the top. Top with the remaining potato slices, remaining sauce and the mozzarella. Cover loosely with kitchen foil then transfer to a baking sheet.

4

Bake for 1 hour, until the sweet potatoes are tender, then remove the foil and bake for a further 10 minutes until the cheese is browned. Let stand for 10 minutes before serving.