Preheat the oven to 190°C.
Spray a frying pan with low-calorie cooking spray and set on a medium heat. Lightly fry the mushrooms for 4-5 minutes until brown around the edges.
Arrange the sausage slices into the bottom of a silicone cake mould. Place the bacon on top, followed by the mushrooms and sliced tomatoes.
Add the eggs and quark to a bowl or jug and season to taste with salt and pepper. Whisk until smooth. Pour the egg mixture over the sausages, bacon and vegetables and sprinkle chopped parsley on top.
Cook for 25-30 minutes, or until the quiche is set and golden in colour.
Serve warm or cold with a good helping of vegetables!