1. Pre-heat an oven to 200°C
  2. To make the sauce; heat oil in a large pan. Add the garlic and onion and cook off for a few minutes until the onions start to gain a light golden colour. Add the mushrooms and the thyme and cook until the mushrooms have softened. Season with salt and pepper.
  3. Add the white wine and cook until it has reduced by half, then stir through the cream and mascarpone cheese.
  4. To assemble: place a layer of sauce on the bottom of the tray. Then layer the lasagna sheets to cover the whole tray. Add more sauce, and the grated cheeses. Repeat until the tray is full.
  5. Cover with foil and place in the pre-heated oven for 45 minutes, or until pasta has cooked
  6. Serve immediately