Soak the bean curd overnight, cut intone inch pieces, set aside. Heat the oil in a large skillet, add lemongrass and saute until golden brown. Stir in chopped chilies and curry powder and add ¼ can of coconut milk to soften the mixture. Add sweet potatoes, white potatoes, and soaked bean curd. Slowly stir in vegetable broth until all ingredients are well mixed. Add bay leaves, cover, and cook for 15 minutes or until potatoes are just about done. Add fried bean curd, mushrooms, cumin, tofu, and remaining coconut milk. Cover and cook for another 5 minutes without lifting the lid. Serve with rice noodles, rice* or bread.