This popular and affordable dish is brilliant for families sitting down for their evening meal together.
1 hour to prepare and cook. Serves 4.
1. Preheat oven to 200C/ 400F/Gas Mark 6.
2. Melt the butter in a saucepan.
3. Stir in the flour and cook for 1-2 minutes.
4. Take the pan off the heat and gradually stir in the milk to get a smooth cheese sauce. Return to the heat, continue stirring. Bring to the boil then simmer for 8-10 minutes.
5. Add ½ the grated cheese and heat gently for 1 minute, whisking until the cheeses have melted, season with nutmeg, salt and black pepper.
6. Put the creamed mushrooms into a bowl and combine with ½ the cheese.
7. Put ½ the cheese and mushroom sauce in the bottom of an ovenproof dish and pour over 1 can of ratatouille. Lay 3-4 pasta sheets over the top then repeat.
8. Pour the remainder of the cheese sauce over the top of the lasagne, sprinkle with the remaining Gruyere and parmesan.
9. Bake in the oven for 30-40 minutes. Allow to stand for 10 minutes before serving.