Heat a pan.
Tip in the grated coconut, chillies, coriander seeds and curry leaves.
Roast on low heat, stirring continuously till it turns light brown in colour.
Add the fenugreek powder and turmeric powder and mix well.
Continue roasting till it becomes dark brown.
Switch off heat and allow the mixture to cool completely.
Grind the mixture to a smooth fine paste with adequate water. Keep aside.
Cook the lentils with adequate water, till just done.
Tip in the vegetables and salt.
Cover and cook till the vegetables are done. (If you prefer firm lentil in your sambar, you may cook the vegetables along with the lentils in one go.)
Dilute the tamarind paste with water.
Add it to the cooked lentil mixture. Mix well.
Add the ground paste and mix well.
Once the mixture comes to a boil, you may add the jaggery(if using).
Allow to boil for a minute.
Switch off heat.
Heat oil in a pan.
Add the mustard seeds.
When they start to splutter, add the cumin seeds.
When the cumin starts to splutter, add asafoetida.
Tip in the sliced shallots, curry leaves and dried chillies.
Saute till the shallots turn slightly brown.
Pour over the Sambar.
Sprinkle coriander leaves.
Serve hot with Rice/Dosa or Idli.