Preheat the oven to 220°C. Cut the potatoes into small cubes and put into a pan of water to boil on the hob. The potatoes will need to cook through but be careful not to over cook them, they still need to hold their shape well.
Wash the leek and thinly slice. Include the whole leek, green and white parts. Slice the mushrooms.
Trim any visible fat from the gammon or bacon and cut into pieces and cut the chicken into small chunks.
Add the gammon, chicken, water, stock cube and mustard powder to the frying pan and spray with frylight. Also add 1 tsp of the garlic granules. Gently saute the meat until it has coloured and then add the leek and mushrooms.
Once the leeks and mushrooms have softened add the spinach and stir until it is lightly wilted. Then take the pan off the heat and gently stir in the light mature cheese spread to create the cheese sauce.
Make a well in the centre of the mixture and add the Quark. Very gently stir working from the centre out until fully combined. It may sound odd, but this will prevent the Quark from splitting! Season with salt and pepper to taste.
If you need to, now transfer the the mix into an oven proof dish. Grate the cheese and sprinkle half onto the top of the mix.
Drain the potato cubes and arrange onto the top of the dish. Spray with frylight and sprinkle 1 tsp of garlic granules over the top.
Place into the middle of the preheated oven for 15 minutes. Then sprinkle the other half of the grated cheese on top of the potatoes, and cook for a furrther 15 minutes. Remove from the oven and serve!