Take 1 cup of Toor dal, also called Split pigeon peas, wash them thoroughly and soak it in water for half an hour. 

Add soaked dal in a pressure cooker along with 1 and half cups of water, ½ tsp of salt and ¼ tsp of turmeric powder.

 Close the lid and let it cook until 3 whistles or until the dal is cooked completely. 

Once the dal is cooked open the lid and lightly whisk with a wooden spoon but don’t grind it completely.

Now let’s prepare the masala, heat 2 tbsps oil in a pan. Once the oil is hot add 1 tsp of mustard seeds, once they start to crackle add ½ tsp of fenugreek seeds, 2-3 dry red chillies, 1 finely chopped green chili 10-12 curry leaves and ¼ tsp asafoetida. 

Give it a mix and cook for 20-30 seconds. 

Now add sliced onion and cook for 2-3 minutes until it turns light golden. 

Now add 2 chopped tomatoes and cook for another 3-4 minutes until they turn mushy. 

Now add 2 chopped drumsticks and mix well and cook for 1-2 minutes. 

You can add more vegetables like carrots, brinjal or pumpkin. 

Now add salt, ( be careful while adding salt because we have added salt in dal as well). 

Then add 1 tsp of Kashmiri red chili powder and 2 tsp of Sambar masala powder, I am using store-bought sambar masala powder you can use any brand you like. 

Give it a mix so that all the vegetables get well coated with masala. 

Now add 4-5 tbsp of Tamarind water. 

Add ½ cup of water mix and cook on low to medium heat for about 3-4 minutes or until all the vegetables are 80 per cent cooked.

Now add cooked dal, chopped onion (cut it in cubes or you can use shallot onions) and a piece of Jaggery that will give a sweet and tangy flavour to sambar.

Cook on medium flame for 3-4 minutes.

Adjust the salt and water as you want.

Sambar should not be too runny or too thick, and now garnish it with fresh coriander leaves.

Tips;

To make Tamarind water soak some Tamarind in warm water then mash it and strain it.

If you want you can add sugar instead of Jaggery.