Take a cooker,add chana dal,chopped ghiya,salt, haldi powder,3 cup of water in it.
Cover with lid and pressure cook for about 4-5 whistles on a high flame.
open the cooker.if needed you can add more water or simmer it so that gravy becomes thick.
For tadka
Take a pan,add ghee,garlic in it ,saute it for 2-3 min until becomes light brown.
Then add onion,green chillies, ginger in it.
Saute it for 5-6 min then add chopped tomato ,saute till the tomatoes soften.keep on stirring.
Then add all spices and and saute it for 2-3 min the oil should start releasing from the onion masala.
Then add the tadka on the boiled dal,and mix well.