Add the soaked moong dal and peeled potatoes to a pressure cooker with enough water. Pressure cook for 2 whistles or until soft.
Once the pressure releases, remove the potatoes and mash them lightly. Keep the cooked dal aside.
Add grated coconut, poppy seeds, roasted gram dal, fennel seeds, and water to a mixer jar. Grind to a smooth paste and keep aside.
Heat oil in a pan. Add mustard seeds, bay leaves, cardamom, cloves, and cinnamon. Saute for a few seconds.
Add sliced onions and saute until translucent. Add ginger garlic paste and green chillies. Saute until the raw smell disappears.
Add chopped tomatoes and turmeric powder. Cook until the tomatoes turn soft and mushy.
Add the mashed potatoes and cooked moong dal. Mix well.
Add the ground coconut paste along with enough water to adjust the consistency. Mix well and simmer for 10 minutes.
Switch off the flame and add lemon juice.
Garnish with chopped coriander leaves and serve hot.