Step 1Place the potatoes in a saucepan, cover with water and boil, covered, 5 minutes. Drain. Prick the potatoes lightly with a fine skewer.
Step 2Place the onion, garlic, ginger, lemon juice, 1 tablespoon of water and 1 teaspoon of salt in a blender and puree.
Step 3Heat the ghee in a saucepan over medium-high heat and fry the cinnamon, cardamom, cloves and bay leaf for 2 minutes. Add the turmeric and stir, then add the blended mixture and fry, stirring, until the onion no longer smells raw, about 1 minute. Rinse out the blender with 2 tablespoons of water, add to the pan with the potatoes and stir well. Cover tightly, turn the heat very low and steam until the potatoes are cooked, 20 to 25 minutes.
Step 4Roast the cumin seeds in a dry pan over medium-high heat, stirring until dark brown, then pound until roughly crushed. Combine the yogurt with the cumin, garam masala and a dash of salt. Serve the potatoes topped with the yogurt mixture and sprinkled with cilantro or chiles.