Pressure cook tur dal in enough water for 2 to 3 whistles, mash well and keep aside.
Meanwhile heat a pan, add quick cooking oats and dry roast over low flame for 3-4 mins. Transfer to a plate and keep aside.
Heat the same pan with oil and 1 tsp ghee. Add mustard seeds and let it splutter.
Add cumin seeds, asafoetida and let them sizzle.
Add onion and cook for a minute till it becomes translucent.
Add tomato, curry leaves, carrots, beans, capsicum, peas and mix well. Let it cook for 2 mins.
Add 1/2 cup water, a pinch of salt for the veggies, turmeric powder and cook for 3-4 mins, till the vegetables are fully cooked.
Add mashed tur dal, tamarind extract, <a href="http://www.ticklingpalates.com/bisi-bele-bath-masala-powder/" target="_blank"><strong>Bisi Bele Bath Masala Powder</strong></a>, salt and mix well.
Add remaining 2 cups water and bring it to a rolling boil. I prefer it very loose so used 2 cups water, if you prefer it a bit thick, add only 1 to 1-1/2 cups water.
Add roasted oats and keep stirring well. Check salt at this stage and adjust accordingly.
Keep cooking over medium flame and the oats will begin to absorb the water and thicken to a porridge consistency.
Take off stove when it is still loose as it will continue to thicken further as it begins to cool.
Oats bisi bele bath is ready to be served.
Transfer to individual bowls, drizzle ghee on top and sprinkle the top with either kara boondhi, mixture or crushed potato chips and serve hot.