For the pork with onions
Season the pork with salt from all sides.
Bring a pot to high heat, add some olive oil and sauté the pork, until nicely browned on all sides. Remove and transfer the pork to a plate.
Remove the fats from the pot and return to the stove. Add the remaining olive oil. Add the onions, season with salt and sauté, until nicely coloured and soft.
Return the pork to the pot with the onions, pour in the wine and cook until all liquids have evaporated.
Add the chicken stock and the oregano, season with salt, bring to boil, immediately lower the heat and cover with a lid.
Cook at very low temperature on the stove or in the oven at 140 degrees C, until the pork has softened.
Add the potatoes, the apple and the raisins and cook until the potatoes have softened.