- Wash and pressure cook potatoes for 2 whistles. Take 2 tablespoons of roasted chana dal in a blender. Grind them into a fine powder. Heat oil in a pan. 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 secs. Next, add the chopped onion and saute it for 2-3 minutes or till the onions turn soft. Add tomato, and dry spices like turmeric powder, coriander powder, garam masala powder, salt, and cook till the tomatoes turn soft. Add fried gram powder and cook for a minute. step to cook tomato along with spices for potato sagu collage Then add 1.5 cups of water, mix well and bring the water to boil. Add boiled & mashed potato, peas, mix well and simmer the potato sagu on a medium-low flame for 3-4 minutes. Once done then turn off the gas. Now add coriander leaves, squeeze lemon juice and mix it well.