Soak the mustard seeds in water and make a paste of mustard seeds along with salt and green chilies.

Chop the sim or flat beans to about 1 cm in thickness.

In a pan/kadai heat the oil. Once the oil is hot add the kalonji or nigella seeds.

As the kalonji starts spluttering add the potatoes and saute them.

Add the turmeric, about ½ cup of water and cook the vegetables covered.

As the vegetables are cooked properly, add the mustard paste and mix them properly.

Cook the vegetables in mustard sauce for about 5 more minutes.