Wash lentils in the pressure cooker.
Add 2½ to 3 cups water, turmeric powder, chopped onions, slit green chillies and chopped spinach.
In a separate bowl, add tamarind, red chilli powder and roughly chopped tomato pieces.
Place this bowl with tomatoes over the spinach.
Close the lid and pressure cook for 3 whistles over high heat and then simmer to low for 5 minutes. Turn off the heat.
Open the pressure cooker once the pressure subsides.
Now mash up everything together. Add sugar, required salt and water to get the desired consistency.
Bring the contents to a boil over medium heat with constant stirring for 2 to 3 minutes and turn off the heat.
Transfer dal to a serving bowl.