Thick and smooth buttermilk can be used in place of yogurt. Do not use grainy yogurt
I prefer making kadhi with regular yogurt, while some use sour curds
Add chopped garlic if you like into tadka
Do NOT overheat the kadhi, it will split and whey will separate out, kadhi turns grainy
Add hing/asafoetida for more aroma but kadhi will not be gluten free