1. Preheat oven to 180ºC.
  2. Melt butter in heavy based medium sized saucepan, add leek and garlic and cook until tender.
  3. Add chicken mince, break up with wooden spoon and sauté until moisture cooks out.
  4. Add mushroom, cook until moisture evaporates.
  5. Add thyme and season with salt and pepper.
  6. Add the flour, stir through and add the milk and stock, bring to the boil, then turn down heat and simmer until thickened.
  7. Add kale, stir and allow to wilt.
  8. Place a ladle of sauce on the base of a baking tray.
  9. Place a layer of lasagna sheets, add 2 ladles of sauce and spread evenly.
  10. Add a third of the mozzarella and parmesan.
  11. Repeat layers twice more.
  12. Finish with a layer of sauce, mozzarella and Parmesan.
  13. Cover with foil and bake for 45 minutes.
  14. Uncover, cook for a further 15 minutes or until golden and bubbly.
  15. Allow lasagna to rest for 15 minutes before portioning and serving.
  16. Serve and enjoy with family and friends!