Soak the bulgur in water, then drain well and let it sit for 30 minutes.

In a food processor, combine the bulgur, boiled potatoes, onion, and tomato paste. Process until you have a dough that can be easily spread in a baking dish. Set aside.

To prepare the filling, sauté the onions in olive oil until soft. Add the walnuts and raisins, stir briefly, then add black pepper and salt. Set aside.

Spread half of the dough in a baking dish using your hands. Add the filling, then cover with the remaining dough. Bake in the oven at 400°F (200°C) until cooked through. Drizzle olive oil on top before serving. Enjoy!