Heat 1 tablespoon of oil in a pan and fry mushrooms. Heat remaining oil and fry onion and garlic 2 minutes. Add green pepper; fry 5 minutes. Add zucchini; fry 7 minutes. Add herbs. In separate dish, mix tomato passata with cream. Add salt, pepper, nutmeg. In heatproof dish, arrange one layer of lasagna (I used 4 pieces per layer), sprinkle with vegetables and cheese, and pour over tomato and cream mixture. Repeat with remaining ingredients. Make 3-4 layers. Last lasagna layers should be covered only by tomato and cream sauce, sprinkled with cheese. Bake about 40 minutes at 350 degrees. Use heatproof dish with cover or aluminum foil.