Ciya Shish Kebabs

My dad says that he doesn't like Shish Kebabs, well this recipe changed his mind. Here is the yummy recipe:

Ciya Shish Kabobs
Serves 4

14oz of ground beef
1 t ground cumin
2 T olive oil, plus extra for brushing
1 cup of plain yogurt
4 flour tortillas
1/2 cup of chopped walnuts
4oz of fresh mozzarella, drained and roughly sliced
1 handful of parsley leaves, finely chopped
4 scallions, finely sliced
Salt and pepper
Sumac (optional)

Preheat the broiler to high. In a large mixing bowl, season the ground beef with a really good pinch of salt and pepper, add the cumin, and mix well. Dividethe ground beef into 8 equal portions, roll out into 5 1/2 inch long sausage shapes, and brush them with a little bit of olive oil. Place the kebabs under the broiler, and broil for 3-4 minutes on each side, or until the are just turning brown and are cooked through, and nice and tender.
Place a tablespoon of yogurt in the middle of each tortilla and spread out with the back of a spoon. Sprinkle with a quarter of the walnuts, mozzarella, parsley, and scallions over each tortilla. Sprinkle each with salt and pepper tucking in the side as you go.
Heat the oil in a skillet over medium heat, then fry the kebabs 1 minute on each side, or until they turn golden brown and crisp. Slice the kebabs in half and serve immediately with the remaining yogurt. Sprinkle with sumac (optional)