Preheat the oven to 120°C.
Season the pork chops with salt, pepper and sumac. Heat half the olive oil in a pan and fry the chops with the fat side facing down first to melt and crisp the fat layer on the side of the chops. Then fry the chops on both sides until golden brown, turning them over only once or twice.
Place the pork chops in an oven dish, cover tightly with foil and place them in the centre of the oven while you prepare the mushrooms and sauce. Add the remaining oil to the same pan and fry the spring onions and garlic until soft.
Add the mushrooms and a small dash of hot water to create steam. Fry the mushrooms while constantly stirring until they are cooked. Season lightly. Remove the whole mushrooms and mushroom pieces from the pan with a slotted spoon and pile them on the pork chops. Place the dish back into the oven.
Add the butter to the pan and when it is melted, add the flour.
Continue stirring until the flour smells like roasted nuts. Add the mushroom or chicken stock, constantly stirring to create a smooth sauce. Add the cream and whisk until it is blended well. Season with a pinch of salt and pepper.
Remove the chops from the oven, pour the sauce over the pork chops and mushrooms and sprinkle with the chives before serving.