Place a large skillet over medium heat and add the oil. When oil is hot, add the garlic and ginger and cook 1 minute. Add the coriander, garam masala and salt and pepper, and cook for 30 seconds. Stir in the tomato paste, and then add the chicken legs. Sprinkle with salt and let them cook for 5 minutes. Add the chicken broth, cilantro and crushed tomatoes, and let it simmer until the chicken is fully cooked, about 30 minutes. Serve with plenty of sauce.