1. In a large bowl, combine the potatoes, bulgur, 2 tablespoon flour, salt, pepper, cayenne pepper and kibbeh seasoning.
2. Knead the mixture, mashing the potatoes and combining the ingredients into dough. Use your fist to mash and knead. If the dough is too dry, you can add a little water if required.
3. Taste the dough for seasoning or spice. Adjust by adding more if required. Keep the mixture aside.
4. To make the filling, in a skillet, heat the olive oil. Add the onion and peppers. Saute until soft and tender, about 5 minutes. Add a little salt and black pepper while sauteing.
5. Add the nuts to the vegetable mixture. Add seven spices and sumac and saute until nuts are nicely toasted, 2-3 minutes. Take pan off the heat.
6. Spray or grease an 8-inch by 8-inch or 1 1/2 quart baking dish/casserole with olive oil.
7. Divide the kibbeh dough into half. Using damp hand, flatten half the mixture into an even thick layer, covering the base of the pan.
8. Spread the vegetable and nut mixture on top.
9. Cover the filling with remaining half of the dough, using damp hands to flatten and layer the dough evenly.
10. Using a damp knife, cut the mixture in the pan into equal size squares. This will help to portion out the kibbeh after it is baked.
11. To bake the kibbeh, preheat the oven to 350 degree F.
12. Drizzle olive oil over the kibbeh in the pan. Place the baking dish in the oven for about 30-35 minutes or until the top is nicely browned and crispy.
13. Remove from the oven and let the pan sit for 5 minutes.
14. Cut the squares and arrange on a platter or on individual plates.
15. Serve warm, with yogurt or a salad on the side.