For this sheem recipe Bengali style, mix the mustard powder with a pinch of salt and 3tbsp water to form a thick slurry. Set aside for 10 minutes.
Wash, peel and cut the potato into wedges.
Wash the green beans. Snip off the ends and remove the strings on either side of the flat bean. Cut each bean into 2-3 pieces.
Heat oil in a pan. Add the nigella seeds and slit green chilli. Allow to sizzle.
Add the chopped potato and hyacinth beans. Stir for 1- 2 minutes.
Sprinkle haldi, salt and sugar. Sauté for a couple of minutes.
Mix in the mustard paste. Add 1 ½ cups water and combine everything well. Put a lid on and cook on medium flame till you get a nice thick consistency. The aloo should be cooked through and the shim should be tender.
The aloo and shim should be nicely coated with the sorshe bata with a wee bit extra mustard sauce on the side.
Serve Sorshe Sheem with steaming hot rice and dal or with any Indian flat bread.