Ingredients:
Tuvar Dal - 1/4 cup
Turmeric Powder - 1/2 tsp
Salt as per taste
Potato - 1, large, cut into 1/2 inch cubes
Drumstick - 1, cut into 3 inch pieces
Brinjal - 2, medium, cut into 1/2 inch cubes
Tomatoes - 2, medium, quartered
Slightly Sour Curd - 1 cup, whisked
Coriander Leaves - 2 tblsp, finely chopped

For the Masala:
Sesame Seed Oil - 3 tsp
Fenugreek Seeds - 1/2 tsp
Coriander Seeds - 3 tsp
Asafoetida Powder - 1/2 tsp
Dry Red Chillies - 3
Bengal Gram Dal - 2 tsp
Green Chillies - 2, chopped
Fresh Coconut - 3/4 cup, grated

For Tempering:
Sesame Seed Oil - 2 tsp
Mustard Seeds - 1 tsp
Cumin Seeds - 1/2 tsp
Dry Red Chilli - 1, halved
Curry Leaves - 1, sprig

Method:
1. Heat oil in a deep frying pan over moderate heat.
2. Add the masala ingredients except coconut.
3. Fry till dal turns golden.
4. Remove from heat and add the coconut.
5. Grind to a smooth paste with 4 to 5 tblsp of water.
6. Keep aside.
7. Wash the tuvar dal and drain.
8. Pressure cook with 1/2 cup of water for 5 minutes.
9. Mix the turmeric powder, salt and 2 cups of water in a pan.
10. Bring to boil over high heat and add the vegetables.
11. Lower heat and cover pan.
12. Simmer for 10 to 12 minutes till vegetables are tender.
13. Add the masala and cooked dal.
14. Simmer uncovered for about 5 minutes, stirring from time to time, till well blended.
15. Mix in the sour curd and heat for a minute.
16. In a separate pan, heat oil and add the tempering ingredients.
17. When the mustard seeds splutter add it to the sambar.
18. Garnish with coriander leaves.
19. Serve hot with cooked rice.

Note: In some parts of South India, the vegetables are mostly optional.