Heat 1 tbsp butter in a pan and fry all the paste ingredients; the cumin seeds, red chillies, green chillies, curry leaves, asafoetida, garlic and ginger for about a minute.
Add the onions in and fry on medium-high heat until they turn translucent and light brown. Add this mixture into a blender, add 1/2 tsp salt and grind to a paste using needed coconut milk(about 1/2 cup). Make the paste smooth (pourable consistency) and set aside.
Heat the remaining 3 tbsp butter in a pan and add mustard seeds. As soon as it starts spluttering add coriander powder and turmeric powder. Fry for a few seconds, stirring continuously. Now add the potato wedges and stir well to coat them with the spice mix. Add some salt and fry on medium-high for a few minutes, until it turns golden brown. It doesn’t matter if it’s still not fully cooked.
Now add the ground paste to the potatoes in the pan and mix again. Let this cook for about 5 minutes on medium-high heat. At this point, pour in the remaining cup of coconut milk and let it simmer for another 10 minutes. Pour about 1/2 cup of water to make it more gravy-like.
Add the frozen peas, let this cook for another 10 minutes. Simmer the sauce till the potatoes are cooked and the gravy has become thick. If it seems too thick, add the needed water to thin it out and add salt to taste (if needed).
Gently immersed the halved boiled eggs in the sauce. Make sure the eggs are fully coated and immersed in the gravy. Simmer the eggs in the sauce for 10 minutes. Sprinkle more chopped curry leaves on top and Serve with hot rice or idiyappam ( Indian rice noodles).
It also goes great with rice. If you are not going to serve the curry immediately add the eggs in just before you are ready to serve.