Slit green chilies. Cut onion into cubes. Cut ¼ inch of bok choy ends and discard.
Separate leaves and thoroughly wash tips after cutting. Often the end of stalks is the place for mud.
Place besan in a bowl. Mix till no lumps exist. Pour buttermilk, salt, and mix till no lumps
Pour your choice of oil in a thick-bottomed pan. Heat on medium.
Add mustard seeds. When they splutter, add cumin. Let it fry for 20 seconds or till fried.
Add curry leaves, ginger garlic paste. Then add turmeric powder. Curry leaves and ginger garlic paste tend to splutter a lot. That's why I put them first and when spluttering settles, I add turmeric powder. Otherwise, turmeric powder splutters around and the color is all over.
Now add chilies, onion, tomato and bok choy. Cook for 2-3 minutes.
Add buttermilk and besan mix. Let it boil in medium high. Once boiled, turn off.
Garnish with cilantro.
Serve with rice or roti.
Recipe by Ujwala's Delicacies at https://www.ujwalasdelicacies.com/bok-choy-and-tomato-kadi/