"This is the world's hottest curry, because it contains the world's hottest chile, the Bhut Jolokia or 'Ghost Chile', which is three times hotter than a habanero. This pan-Asian dish is not for the faint of heart. It is atomically spicy! Enjoy!"
Place tomatoes, water, garlic, ginger, tomato puree, salt, ghost peppers, chili powder, garam masala, cumin, coriander, fenugreek, and black pepper into a blender and pulse several times to chop. Blend the ingredients until liquefied. Be careful, ghost chilies will burn eyes, mouth, or nose if touched.
Pour the blended mixture into a large bowl and stir in lamb to coat; let lamb marinate at least 1 hour in refrigerator.
Heat clarified butter in a large pan over medium-high heat and cook onion until lightly golden brown, 10 to 15 minutes, stirring constantly. Pour the lamb and marinade into the skillet and bring to a boil; cook and stir until sauce begins to thicken, about 5 minutes. Reduce heat to low and simmer until lamb is tender, about 20 more minutes. Garnish with cilantro to serve.