Soak ½ cup cooked rice in ½ cup water in a clay pot for about 10-12 hours or overnight.
Next day , transfer fermented rice to a blender and blend to smooth paste.
Transfer blended rice into a mixing bowl.
Whisk ¼ cup of homemade curds and add to rice paste and stir well. Preferably add slightly sour curds as it tastes more good.
Now add salt to taste and mix well.
In a season pan / tadka pan , heat coconut oil , add mustard seeds ,jeera seeds , urad dal , chopped curry leaves , choppeds green chillies and fry well.
Add chopped onions and fry till it turns light brown .Turn off the stove
Now add in grated ginger , hing and mix well.
Pour temper over the prepared rice kanji.
Garnish with chopped coriander leaves and serve.
Clay pot is used for fermentation , as science says it provides micro-oxygenation, including enzymatic reactions for producing unique flavors. If you don't have clay pot , you can use steel or glass vessel but clay pot is recommended.
Fermented rice needs to be mashed well , you can either squeeze with clean hands or use fork or blend in a mixer.
Use slightly sour curds , it adds more taste to rice kanji.
Tempering with coconut oil adds lots of flavor and tastes really good.
You can use any type of cooked rice , best way to use left out rice.