Cook chicken in ghee till it turns opaque, then stir in onions. Turn down the heat, then sprinkle salt over onions. Cook for a bout 10 minutes, stirring regularly. Stir in garlic, ginger, turmeric, cayenne and garam masala. Stir till well coated. Add tomatoes and coconut. Simmer about 20 minutes, stirring periodically. Serve over rice, or with naan