In a large saucepan, dry roast all the spices in a saucepan (except coconut, red chillies and curry leaves) on medium low for about 3 to 4 minutes till lightly roasted and you get a nice aroma. Keep aside.
In the same pan, roast the coconut, red chillies and curry leaves for a few minutes till the coconut is lightly browned.
Mix both the spices and coconut mixture and make a fine powder in a coffee grinder or blender. Keep aside. (This can be stored in the refrigerator for about a month or in the freezer section for up to 3 months).
To make the oats bisi bele bath:
Soak tamarind in 1/2 cup of water for about 20 to 30 minutes.
Cook all the cut vegetables in a pressure cooker (for 2 whistles) or in a saucepan with plenty of water.
Pressure cook toor dal for 3 to 4 whistles till soft and well cooked.
Roast the oats in a dry saucepan for a few minutes on medium low heat (this prevents bisi bele bath from becoming sticky after cooking).
Squeeze and extract tamarind water from the soaked tamarind; keep aside.
Now, in a large saucepan, heat oil and 1 tablespoon ghee. Once they are hot, add the mustard seeds. As soon as the seeds start to splutter, add curry leaves and hing.
After a few seconds, stir in the cooked vegetables along with the water in which it was cooked, turmeric powder, salt to taste and cooked dhal. Add extracted tamarind water to the mixture. If you are using tamarind paste, add it now.
Mix well and once it comes to a boil, add 2 to 3 tablespoons of bisi bele bath powder and give it a good stir. Add more water if necessary.
Now, when the vegetables and spices are well mixed, and the mixture comes to a boil, add roasted oats and stir well. Add more water (about 1 cup) and give it a good mix.
Do a taste test and add more tamarind, salt or bisi bele bath powder as needed. Cook for about 3 to 4 minutes till it is well cooked and soft.
Stir in 1 to 2 tablespoons of ghee and mix well.
For additional crunch, roast few cashew nuts or peanuts in a little hot ghee and add to the oats bisi bele bath. Mix well.
Serve hot savory, spicy, south Indian oats bisi bele bath with additional ghee along with potato chips, boondis (crispy deep fried chickpea batter balls), curd etc.
