Preheat the oven on 200c.
Spray a large oven dish with frylight and layer the base with the sliced potatoes, season, spray again and place in the oven for 15 minutes.
Meanwhile, spray a large frying pan with frylight and saute the onions and garlic until tender.
Now add brown the ground beef or Quorn along with the herbs and spices and fry until browned.
Stir in the tinned tomatoes, puree and vinegar and fry for another 10 minutes and spoon evenly over the potatoes.
In a separate bowl, whisk together the egg, mustard powder and spread on top of the meaty or veggie mince layer.
Finally sprinkle the cheese on top, then lower the oven to 180 degrees and bake for a final 15 minutes and enjoy!