Preheat the oven to 200C/180C Fan/Gasoline 6.
Warmth the olive oil in a massive, non-stick saucepan and fry the onion for 3–4 minutes, or right until softened and evenly browned, stirring. Increase the aubergine, courgette, pepper and mushrooms and fry for 12 minutes, stirring regularly.
Insert the garlic and cook for a few seconds much more, then stir in the crimson lentils, tomatoes, Italian seasoning, sugar and crumbled stock cube.
Refill 1 of the tomato tins with h2o (400ml/14fl oz) and pour into the pan. Stir effectively, deliver to a simmer and cook dinner for 15 minutes, stirring frequently. Incorporate the spinach leaves, a handful at a time and prepare dinner for 1–2 minutes additional.
Even though the veggies are simmering, make the white sauce. Heat the oil in a medium saucepan. When it is warm include the flour and cook dinner, stirring all the time, for 1 minute. Stir in the milk, yeast, bay leaf and nutmeg and period very well with salt and pepper.
Bring to a simmer, whisking continually with a metallic whisk in excess of a reasonable warmth for 4–5 minutes, or until eventually smooth and thickened. (Use a silicone included whisk if working with a non-adhere saucepan.) Regulate the seasoning to flavor – you are going to need additional black pepper than you could envision.
Spread a 3rd of the vegetable combination above the foundation of a 2½ –3 litre/4½– 5 pints ovenproof lasagne dish and deal with with a solitary layer of lasagne sheets. Major with one more 3rd of the vegetable combination (really don’t get worried if it doesn’t deal with evenly) and a second layer of lasagne.
Pour in excess of just less than fifty percent of the white sauce, following taking away the bay leaf, and extremely gently best with the remaining vegetable mixture. Complete with a ultimate layer of lasagne and the rest of the white sauce.
Bake for 35–40 minutes, or the pasta has softened and the topping is nicely browned and effervescent. Stand for 5 minutes just before reducing to permit the filling to settle.