1. In a large bowl, mix together the yogurt, lemon juice, half the garlic, 1 tsp salt and the cumin . Transfer half the yogurt mixture to a small bowl. Add the shrimp to the large bowl and mix; cover and refrigerate for 15 minutes.
2. In a medium saucepan, heat 1 1/2 TBS olive oil, the crushed red pepper and remaining garlic over medium heat for 2 minutes. Add the chickpeas and cook, stirring, for 4 minutes. Add the tomatoes and remaining 1 tsb salt, cover and cook for 5 minutes. Lower the heat and keep warm until ready to serve.
3. Rub a grill pan with the remaining 1/2 TBS olive oil and heat over high heat. Add the marinated shrimp to grill and cook on grill, turning once, until cooked through, about 3 minutes on each side.
4. Top the chickpeas with the shrimp and service with the reserved yogurt sauce.