Heat oil in a pan over medium heat. Add mustard seeds and fenugreek seeds.
Once the mustard seeds pop, add onions, green chillies, garlic, curry leaves and sauté for a minute.
Add tomato pieces and a little salt. Cook till the tomatoes become mushy.
Now add red chilli powder, sambar powder (optional) and mix well. Sauté for 2 minutes.
Add the mixed vegetables, little coriander, tamarind pulp, 2 cups of water, jaggery and mix well.
Close the lid of the pressure cooker & cook for one whistle.
Turn off the heat & open the lid once the pressure subsides.Garnish with coriander.
Serve hot with steamed rice, mudda pappu (boiled lentils) and a dollop of ghee.