Make a checklist. Keep all ingredients close by

Marinade: Heat oil in a heavy pan over medium heat and add mustard seeds, cumin seeds and spices.. Add all the spice powders.
Dissolve the tamarind paste in ¼ cup of water and add to the pan. Add salt. Simmer the fire. Let the tamarind thicken a little. Turn off the stove. Let marinade coat all sides of the taro. let them soak in the marinade for 30 minutes.

Then turn on the stove. Roast the taro in this pan over low flame. Then turn the veggies now and then slowly. without mashing the taro. The roast will be done in 10-15 minutes.
Taste and serve. Tastes divine when served with curd rice