To make the creamy sauce, whisk cream and milk on a low heat.
Spoon in pumpkin purée.
Sprinkle in black pepper.
Add the cheese a little at a time and whisk so that it melts.
When all of the cheese has dissolved, take the sauce off the heat.
To make the filling, fry mince with mushrooms and onion on medium heat for 10 minutes.
Stir in passata and chopped tomatoes, sprinkle in black pepper.
Add a third of the mixture to a baking dish and top with lasagne sheets and plenty of cream sauce.
Repeat two more times.
On the final layer top with plenty of grated cheese.
Bake in oven at 180C for 30 minutes.