In a large heavy skillet over medium heat, cook ground lamb until evenly brown. While cooking, break apart with a wooden spoon until crumbled. Transfer cooked lamb to a bowl, and drain off all but 1 tablespoon fat. Saute onion until soft and translucent, about 5 minutes. Stir in garlic, and saute 1 minute. Stir in garam masala and salt, and cook 1 minute. Return the browned lamb to the pan, and stir in tomato paste and beef broth. Reduce heat, and simmer for 10 to 15 minutes or until meat is fully cooked through, and liquid has evaporated.