In a pressure cooker take all the potato cubes / peeled baby potatoes along with turmeric powder and salt.
Pour enough water and pressure cook till boiled. (Donot over boil the potatoes, else the end result will be completely a messy)
Drain the potatoes and keep aside in a bowl.
Now in a blender jar, make a fine paste of mustard seeds, grated coconut and 3-4 no of green chilies.
Add this paste to the boiled potatoes.
Heat mustard oil in a tadka pan.
When oil is hot, add panch phoran and allow to splutter.
Then turn off heat and pour this tempering onto the bowl containing the potatoes.
Meanwhile, turn on the steamer.
Now mix everything gently (do not break the potatoes) till all the potatoes are well coated.
Take a container (supposed to put inside the steamer pot) and lined a banana leaf.
Then transfer the potatoes into it and top it with another banana leaf.
Put on the lid and steam for 10-12 minutes.
Turn off the heat, take out the container from the steamer.
Serve Bhapa Aloo hot with steamed rice-dal combo or even with poori, paratha !