Preparation

• Put the potatoes in a large pot of water, season generously with salt and bring to a boil. Reduce the heat and simmer until tender, 15 to 18 minutes. Drain.
• Melt the butter in the same saucepan. Add the onion, and cook, stirring, until very soft, about 5 minutes. Add the ginger and garlic, and cook, stirring, until fragrant, about 30 seconds. Stir in the garam masala, turmeric, cumin, and cayenne; cook, stirring, until fragrant. Add the cream and 1 tsp. salt, and bring to a simmer.
• Return the potatoes to the pan and mash. Stir in the peas and warm through. Stir in the cilantro, and serve garnished with more cilantro and a lemon wedge, if you like.