Rinse the lentils and rice at least three times or until the water runs clear. Add to a bowl and pour 3 cups of water and let soak for 30 minutes.
Heat ghee in a heavy botton pot with lid(or IP or Pressure cooker).
Add minced ginger, hing and black peppercorns to the warm ghee and saute for few seconds. Add the onions and cook them for a couple minute until translucent and starting to turn light brown.
Add the soaked lentils and rice along with the water. Sprinkle turmeric powder. dd another cup of water. Stir well and taste the salt. Adjust salt.
To slow cook :- Bring to a boil, cover and let cook for 20-35 minutes until lentils and rice are soft. Stir often and mash using back of spoon while the khichdi cooks. Adjust consistency with warm water as desired. Add tempering before serving and mix. Serve warm.
To cook in Instant Pot or Pressure Cooker :- Close the lid and pressure cook. For the quantities mentioned in the recipe, on medium heat, it takes about 8 minutes in an Instant pot and 3-4 whistles in a pressure cooker. Let pressure release naturally in both cases, add more water an cook a little to adjust the desired consistency and then proceed to adding tempering.