Boil the 4 eggs and deshell. Poke them with a fork randomly or make slits on it. Set it aside.
Pour oil to a heated pan over medium heat. Add mustard seeds and fennel, allow to crackle.
Add sliced onions and salt. Sauté them until lightly golden.
Add crushed ginger-garlic and saute until the onions turn slightly caramelized.
Spoon in turmeric powder, chili powder, black pepper, Garam Masala and coriander powder. Saute for a few minutes or until the raw smell goes.
Add finely chopped tomato and cook until it becomes mushy. Pour hot water and mix well. Cook until the water evaporates.
Transfer the boiled eggs and a few sprigs of curry leaves. Fry them for 10 minutes, until the onions caramelize and the egg roast turns aromatic. Taste test and add more salt.
Serve egg roast hot with appam, puttu, chapathi, or naan.