Preheat the oven to 325 degrees F (165 degrees C).
Place the cubed pork and potatoes into a glass baking dish. In a small bowl, mix together the yogurt, curry powder, milk, tomato purée and paprika. Pour the yogurt mixture over the pork and potatoes, and stir to coat.
Cover, and bake for about 1 hour in the preheated oven. Remove from oven, and stir in mango, green onion and sour cream with salt and pepper to taste. Return to the oven for another 10 minutes, or until pork is tender. Serve over cooked white rice.