Place the onion, swede and carrots into the bowl of a food processor.
Then add the cinnamon, herbs and flour and whiz everything until it is all finely chopped but stop before it turns into a purée.
Place it all in a casserole dish, add the beef and season generously with salt and pepper.
Next mix the tomato purée and stock together in a jug, stir this into the casserole and give it a good mix.
Place the casserole over a gentle heat and bring it up to simmering point.
Cover with the lid and place it in the pre-heated oven on the centre shelf to cook for 2 hours.
About 30 minutes before the time is up, peel the potatoes, cut them into even-sized chunks and place them in a saucepan.
Pour boiling water over, add some salt, cover and simmer for 20-25 minutes or until they are tender when pierced with a skewer.
Drain the potatoes, cover with a clean tea cloth for 5 minutes to absorb the steam, then, start to mash the potatoes (an electric handheld whisk on slow speed is best for this), gradually adding the quark, milk and a seasoning of salt and freshly milled black pepper and continuing to whisk until the potatoes are light and fluffy.
At this point remove the casserole from the oven and increase the temperature to 200C or 400°F.
Cover the meat mixture evenly with the mashed potato.
Now slice the leek lengthways into four and chop each length into 1/4 inch slices.
Rinse and dry them, then cover the potato with chopped leek, pressing them gently into the surface.
Finally cover the leeks with grated Cheddar and then sprinkle with the Parmesan.
Return the dish to the oven on a high shelf for 25 minutes or until the top is golden and crusty.