Boil plenty of water in a big pan, add one tablespoon olive oil. When the water begins to boil, put in the lasagne sheets and cook till al-dente.
Drain and refresh in cold water.
Drain and set aside to cool.
Preheat the oven to 160°C
Heat one tablespoon olive oil in a non-stick pan, add celery (if using), capsicum and 1/2 of the crushed garlic and stir.
Add tomatoes and stir and cook.
In another pan, add 2 tablespoons olive oil, remaining crushed garlic, fry for a minute, add the diced mushrooms, sauté on high until the moisture dries out, add the chopped spinach and sauté again until it’s dry. Add salt, crushed black pepper, mix well and set aside.
Meanwhile prepare the tomato sauce. Add salt, freshly ground black pepper powder and stir. Tomato sauce is ready.
Take a baking dish and pour some white sauce at the base.
Place a lasagne sheet, spread some of the tomato sauce over it.
Sprinkle a few basil leaves.
Cover with another large lasagna sheet.
Spread some white sauce and spread some mushroom-spinach mix.
Spread some tomato sauce and followed by another lasagna sheet.
Similarly make layers till all the lasagne sheets, white and tomato sauces, mushroom - spinach mix are used ending with a layer of tomato sauce.
Spread the cheese and remaining basil leaves.
Bake in the preheated oven for 20 minutes.
Serve hot.
