1. Spray your grill with cooking spray and set heat to medium
2. In a large bowl, combine meat, salt and black pepper. Shape mixture into 4 equal balls. Press 1 cube of Gorgonzola chees into the center of each ball, covering cheese completely with meat. Shape balls into patties, each about 1 inch thick.
3. Add burger to grill and cook 5-6 minutes per side.
4. Meanwhile, mix next 7 ingredients well in a small bowl.
5. Place burgers on rolls and spoon 2 tablespoons yogurt sauce over each burger.