Heat oil in a pan. Then add mustard, cumin, fenugreek seeds, chana dal and urad dal.
Fry until the dals turn golden. Then saute ginger until it turns aromatic for 30 seconds.
Add curry leaves and green chilies. Saute until the leaves turn golden.
Next add onions and fry till they begin to turn pink. They should be partially cooked yet keep the crunch. Turn off the stove.
Next add turmeric, hing and salt. Cool this completely.
Meanwhile add curd to a bowl and whisk it well. Then add the cooled tempering to this along with coriander leaves. Taste and add more salt if needed.
Serve majjiga chaaru with rice.