In a large, heavy-bottomed skillet, heat the oil over medium heat. When hot, add the hot curry powder and stir it around for 30 seconds. Add the onions to the pan and saute until they are tender and a bit golden. When you’re there, add the carrots, potatoes, and minced garlic. Give it all a good stir, and then add about a half cup each of water and coconut milk. Stir in the turmeric, salt, and coriander. Reduce the heat to low and cover it. Check every so often to stir the pot and check the moisture level. When the moisture is almost all absorbed, add more coconut milk and water, in equal parts. Continue to cook, stir, and add liquid until the vegetables are very tender and the curry is nice and thick. At this point, taste it to check that the spice levels are where you like them. When you’re there, stir in the peas and the rest of the coconut milk (and water if necessary), and cook it for.