1. Grind pistachios, coconut, sesame seeds, cumin seeds, salt and pepper in a coffee grinder; transfer to a medium bowl.
2. Cut beef into 24 cubes and add to bowl with spices; toss to coat. Thread 6 beef cubes on each of 4 skewers.
3. Bring chicken broth to a boil in a medium pot. Add cauliflower and couscous and simmer over medium-low heat until liquid is absorbed. Turn off heat and cover pot.
4. Preheat the broiler. Place kebabs on a foil-lined baking sheet and broil 4 minutes; flip and broil 4 minutes more, or until beef is rosy in the center.
5. Fluff couscous with a fork. Stir in mint, olives, lemon zest, lemon juice and oil; season with salt and pepper to taste.