In a kadai heat 2 tbsp oil, cumin seeds, and hing. Sauté for a minute.
Then add chopped onion and sauté till onion become translucent.
Now add ginger and green chili paste. Sauté it.
Then lower the flame and add turmeric powder, red chili powder, coriander powder, and cumin powder, and some water. Mix well and sauté masala till oil separates from its sides.
Add tomatoes and salt. Cook till tomatoes become soft and mashy.
Add boiled peas and potatoes mixture. Mix well.
Then add ½ cup water and mix well.
Cover and cook ragda for 10 minutes on low flame.
Add chaat masala, garam masala and lemon juice. mix well.
Ragda is ready.