In a large casserole dish over a moderate heat start by adding half the oil and sweating the veggies, but not the tomatoes!) with the chopped parsley stalk, the thyme leaves and the garlic. Once they have cooked down a little scrape them all out of the pan and turn the heat up, add the rest of the oil and then the venison mince, seasoning generously. Stir the meat around a bit allowing it to brown but not allowing it to clump up too much into large chunks. After 5 minutes or so, reduce the heat back to a more moderate level and re-introduce the veggies, then add the wine and allow this to cookout – reduce the wine down to almost nothing, then turn down the heat, then add the tomatoes and bring the whole show to a simmer. Add the pork skin if you are using it, along with the chilli flakes and the dried oregano, stir, simmer and reduce the heat to the lowest you can manage where you still get a little bit of gentle simmering in the pot, pop the lid on and stir every ten minutes, adding a little water if it starts to get a bit too concentrated, as you go along. Continue cooking like this for at least 1.5 hours.