Preheat oven to 200°C.
Halve the aubergines and place cut-side down on a lined tray. Trim the garlic bulb, drizzle everything with olive oil and roast for 40 minutes until soft.
Dice the onion, chop the sun-dried tomatoes and blitz the walnuts and oregano to a crumb.
Sauté the onion with a pinch of salt in olive oil. Add the garlic, paprika, tomato purée, oregano and sun-dried tomatoes. Stir in the lentils, balsamic and tinned tomatoes, crushing with a spoon. Pour in the water and simmer for 10 minutes.
Scoop the aubergine flesh and roasted garlic into the ragù. Stir well and season.
Break the lasagne sheets into pieces and stir into the sauce. Drizzle with cream, scatter over the walnut crumb and cheese and bake for 30 minutes. Rest for 10 minutes before serving.
