1. Step 1

Preheat the oven grill to high. Heat the oil in a large deep oven-proof frying pan over high heat. Add the sage leaves and cook for 30 seconds or until crisp. Remove the sage and set aside. Add the fennel, sausage mince and garlic, breaking up the mince with the back of a wooden spoon. Cook for 5 minutes or until the fennel is caramelised.
2. ##### Step 2

Add the tomatoes and stock and bring the mixture to a simmer. Add the pasta sheets, submerging them in the liquid, and cook for 15 minutes, covered, until they are just tender and the sauce has reduced.
3. ##### Step 3

Meanwhile, combine the mascarpone, parmesan, mozzarella and 60ml of water in a medium bowl. Season with salt and mix well. Spoon the cheese mixture over the lasagne. Place the frying pan on a baking tray and place it under the grill, then cook for 6-8 minutes or until the top is bubbling and golden.
4. ##### Step 4

Set the lasagne aside for 10 minutes to set before serving, scattered with black pepper and the crispy sage leaves.