Place all of the ingredients in a blender and puree until smooth, cover and set aside.
Puree the nuts, garlic and kale in a blender. Turn the blender to a low setting, continue to puree while gradually adding the oil. Add the lemon juice, salt and water, puree briefly. Cover the pesto and set aside.
Cook the lentils (uncovered) in water for approx. 15 mins., drain. Sauté the onion and garlic in oil, add the mushrooms and cook for approx. 3 mins. Add the tomatoes, bring to the boil, simmer for approx. 5 mins. Add the drained lentils, mix everything together, season.
Transfer one third of the lentil ragout to the prepared dish, layer the lasagne sheets, pesto and the remainder of the lentil ragout in the dish, top with the cashew parmesan.
Bake for approx. 30 mins. in the centre of an oven preheated to 180°C.