Heat oil in pressure cooker and mustard seeds.
Add onion and saute till it turns brown.
Add ginger and salt, turmeric powder and red chilly powder.
Saute for a minute. Add red lentils and mix well.
Add some water and pressure cook for 3 whistles.
Let the pressure cooker cool down. Open the lid and cook on high flame till all the water evaporates.
Garnish with chopped onion, coriander leaves, and squeeze some lemon juice. Serve hot.