Put the bulgur in a pot and pour over the hot stock. Cover and leave to stand for 15 minutes. Meanwhile, soak eight bamboo skewers in cold water (to prevent them from burning on the grill). Remove the lid from the pan and cook the bulgur over a low heat for 4-5 minutes, stirring frequently, until the excess liquid has evaporated, but the mixture is still moist. Tip onto a tray, spread out and leave to cool.
Tip the cooled bulgur into a bowl. Add the lamb, onion, pine nuts, cilantro and dry spices and season to taste. Thoroughly mix together with your hands. If you prefer a smoother-textured kibbeh, transfer the mixture to a food processor and blend for a few seconds. (You may need to do this in batches.)
Preheat the grill to medium. Divide the lamb mixture into 16 pieces and shape into oval-shaped balls (kibbeh). Thread the kibbeh onto the soaked wooden skewers, putting two on each skewer. Arrange, side by side, on a foil-lined grill tray and grill for 4-5 minutes on each side until well browned and cooked through. Remove and wrap loosely in the foil to keep warm.
Put the pita breads on the grill tray and grill for about 30 seconds on each side to warm them; don't let them brown or cook for any longer, or they will be too brittle to split open. Run a knife down one long edge of each pita and gently open out to make a pocket.
Half-fill the pita bread pockets with the shredded lettuce, carrot, cucumber and radishes. Slide the kibbeh off the skewers and divide among the pita pockets. Add more salad to taste. Drizzle each one with a spoonful of tzatziki and serve immediately.
Variation: Tzatziki is a mixture of yogourt, cucumber, mint and garlic. If you prefer, use reduced-fat hummus mixed with a little low-fat plain yogourt. Or, for a really low-fat dressing, combine 1⁄2 cup low-fat plain yogourt with 1⁄4 cup chopped fresh mint.
Each serving: 40 g protein, 26 g fat of which 9.5 g saturates, 53 g carbohydrate, 11 g fibre, 622 Calories