Method for idli:
Wash urad dal and rice in water and soak them for 5 to 6 hours or overnight.
The next morning, grind them with little water until granular.
Transfer the mixture to a vessel, add salt and leave it overnight.
Once the batter is properly fermented, it will rise and turn smooth and double its mass. The idli batter is ready.
Place an idli maker on gas over medium flame and fill 2 cups of water in it.
Pour the mixture in each greased plate of an idli maker, steam for 5 minutes on medium flame.
After 5 mins, check de-mold idlis in a crisper using a knife. The idlis should come out soft and easy. Do the same for remaining batter and the idlis are ready.
Method for Sambar:
Pressure cook toor dal up to two whistles on low flame.
Once cooked, release the pressure and keep it aside.
In a nonstick pan, heat oil. Add dry red chillies, curry leaves, methi seeds, cumin seeds, mustard seeds and let them splutter.
Add onions and cook until golden. Add tomatoes and salt, cook on medium flame until tomatoes turn soft.
Next, add turmeric powder, red chilli powder, coconut powder (optional), drumstick and stir fry for 5 mins on medium flame.
Pour cooked toor dal and mix well.
Add some water to adjust its consistency.
Add tamarind pulp and sambar masala and bring it to simmer or cook until the vegetables are soft.
Once cooked, turn off the flame and add coriander leaves. Pour it into bowl along with idlis in plate.