Sambar is essential in tamilnadu cusine. You may choose your vegetables like  Ash gourd,lady's finger,carrots,potatoes,beans,capsicum . My favourite is capsicum and ash gourd.  You can also make kadhamba sambar with potatoes,carrots,beans.

Toor dhall - 200 grams cooked

Tamarind - lemon size

Fenugreek

turmeric

Asafoetida

vegetable of your choice (mine: capsicum cut into cubes)

Water

Salt

Soak Tamarid in hot water and when cool extract  tamarind juice and store aside

In a thick bottomed  pan add a teaspoon of oil and fry the capsicum once done add tamarind  paste /juice and bring to boil ; now add sambar powder,dhall,turmeric powder and salt and cook for 10 minutes until the raw smell leaves and the capsicum sambar aroma fills the kitchen.In a small pan add a teaspoon of oil , add mustard,1/2 teaspoon of fenugreek ,1/2 teaspoon of Asafoetida,curry leaves and add to the sambar and remove from stove.