Heat the oil in a big pot.
Add the sliced onions.Cook on med-low heat, stirring often, till they are soft, light brown, and slightly mushy.
Once the onions are ready, add the Curry Leaves, cumin, fennel ,mustard, Ginger, Garlic & Green Chili. Also add the dry ground spices- pepper, chili powder, Coriander Powder,Salt & Turmeric
Give it a mix and Saute for about 20-30 seconds.
Add the chopped tomatoes and cook at medium flame for 15-20 minutes, till the tomato is mushy and mixes with the rest of the masala.
Keep sautéing the masala till you get a jammy consistency of the onions and tomato.Add 2-3 tablespoon of water if the onions and tomatoes are burning.
Use a heavy Ladle or potato masher to lightly mash the onion-tomato base sauce.
Take off the heat.Add boiled eggs- whole or halved.
Garnish with coriander and serve with parathas or rice.