Wash the potatoes. Peel them and cut them into thin slices. Then boil them in water till they are 80% done. Remove and strain.
In a pan, heat oil. On medium heat, fry green chillies.
When the chillies are fried well, add onions and fry them till they are slightly brown. Keep aside.
In a separate bowl, beat the eggs with 3/4 teaspoon salt, black pepper powder, and coriander leaves. Transfer the fried chillies and onions to this egg mixture.
Take a fresh pan. Apply oil on its surface and spread a layer of potatoes. Sprinkle some salt over it. Keep on medium heat and cook until the potatoes brown a bit.
Now add the egg mixture.
Cover the eggs with another layer of sliced potatoes. Sprinkle some salt on the potatoes.
On low to medium heat, let it cook for about 5 minutes.
Cover this pan with a plate and flip the half-done Omelette to the plate. By flipping, the uncooked part of the Omelette will be at the bottom and the cooked part on the top.
Apply 1/2 tablespoon of salted butter to the pan.
Now slowly and carefully slide the Omelette from the plate onto the pan. Now the uncooked part will be in direct contact with the pan.
Continue cooking at low to medium heat for another 3-5 minutes. Apply the rest of the salted butter on the sides.
Then transfer to the serving plate. Garnish with any herb of your choice. I garnished it with chopped coriander leaves and rosemary.