Wash and pressure cook potatoes for 2 whistles or use an Instant Pot to boil the Potatoes.
Take 2 tablespoons of roasted chana dal or roasted bengal gram in a blender. Grind them into a fine powder.
Heat oil in a pan/kadai. Once the oil is hot, add mustard seeds, cumin and let them splutter.
Then add urad dal, chana dal, and saute till the dals become light brown.
Then add green chilies, ginger, curry leaves, hing, and saute for 30 seconds.
Next, add the chopped onion, turmeric powder, and salt and saute it for 2-3 minutes or till the onions turn soft.
Add 2 tablespoons of fried gram powder in a small bowl, add some water, and stir well. Add the mixture to the kadai and cook for a minute.
Then add 1.5 cups of water, mix well, and bring the water to a boil. Add boiled & mashed potato, coriander powder mix well, and simmer the Bombay sagu on a medium-low flame for 3-4 minutes. Once done, then turn off the gas.
Now squeeze lemon juice, add coriander leaves, and mix it well.
Serve Potato/Aloo Sagu recipe with poori, chapati, dosa, or idli.