Kosha means frying onion, tomato, and spice mix in oil for a longer period over medium-high flame, and water is added little by little and cooked until the spices are well cooked and changed color to blackish and also the oil start releasing from the gravy. Dim Kosha comes with thick onion blackish or dark brownish colored gravy. It goes well with Paratha or luchi (puri), but itii s not a good combination with plain rice. Dimer jhol or dalna is yellow colored light watery jhol (or you can say also stew), which can go well with white rice. Hanser Dim Kosha is tastier than regular Dimer Jhol due to addin gmore oil and spices.
Take 4 boiled duck eggs and 2 potatoes in a mixing bowl, and add salt,turmeric powder, and red chili powder.
Give a nice mix.
Heat oil in a Kadai
Add the eggs to hot oil and fry them for 2 minutes or till the color changes to light brown
After frying the eggs add the potato to the same oil and fry them for 2 minutes
Now add bay leaf and whole spices (cardamom, cinnamon, cloves, and peppercorn) for tempering
Add the chopped onions, and fry them till they become soft, but don’t make them crispy ( idea is to make gravy thick with soft onion which will be meltedafte rward)
Now add ginger-garlic and red chili paste
Add the chopped tomato and salt ( as salt helps to melt the tomato)
Add turmeric, cumin-coriander, and red chili powder
Now add a little (1-2 tbsp) water (to prevent burning of the spices) and add garam masala;
Stir them continuously till the spices are cooked well.
Now add the fried potato and sauté them for 10-12 seconds
Add water (2 cups) and cover the lid and allow them to cook for 5-6 minutes
Open the cover and add the fried eggs (give a small cut in one side of theeggs before adding in the gravy)
Turn off the flame and transfer them to a serving plate and serve hot with paratha or luchi or fried rice