Wash the parwals and then scrape off the hard skin. Cut the pointy ends and keep aside.
In a kadai, heat mustard oil and temper with a couple of green chillies, bayleaf, cardamom, cinnamon and cloves. Once the spices have browned a bit, add the parwals.
Stir fry them on medium heat for a couple of minutes.
Then in a small bowl, take the turmeric powder and cumin powder and make a slurry with 2 tbspof water.
Add this slurry to the parwal and coat the spices with the vegetables. Add salt.
Sprinkle some more warm water if required and stir fry on medium heat till the raw smell of turmeric powder goes away.
Then add the milk and let it simmer for a minute. Then cover and cook the parwal in the milk.
Check time and again if the parwals have softened or if the spices are sticking to the bottom. In that case, just spirnkle some warm water.
Once the parwals have softened, sprinkle sugar, ghee, Bengali garam masala and more split green chillies.
Give it a boil and the milk should have thickened and become creamy. If not, then just make a slurry with 1 tsp of maida and milk and add to the gravy.
Once everything has come together nicely, turn off the heat.
Serve doodh potol with rice or with luchi.