In a medium mixing bowl, combine the meat, prunes, shallots, garlic, parsley, orange zest, allspice, egg, the 1 tablespoon olive oil, the salt, and pepper. Mix well with a fork. Cover and refrigerate for 30 minutes, or up to 8 hours. (If you don't have that kind of time, refrigerate for just 10 minutes).
Remove the bowl from the refrigerator. Wash your hands well, and keep them damp. Scoop out rounded tablespoons of the mixture and roll them into balls between your palms. Set aside in a single layer on two plates until you've used up all the meat. Wash your hands thoroughly again.
Heat 1 teaspoon olive oil in a large nonstick skillet over medium heat. Add half of the meatballs in a single layer without crowding. Cook for 8 to 10 minutes, stirring the meatballs gently around the pan to brown them all over. Set aside on a clean plate and cover with foil while you cook the second batch. Return the first batch to the pan, cover, and reheat for 2 minutes. Transfer to a serving dish, sprinkle with parsley, and serve with couscous and Greek-style yoghurt.