Soak Tamarind in warm water for 20 minutes and extract approximately 3 cups of water. The amount of tamarind depends upon the variety of tamarind you are using. Some might be very tangy with small amount, some might be otherwise. So soak and extract accordingly. The variety i used is very tangy.
Heat oil in a deep pan/Kadai, splutter mustard seeds, add methi seeds/fenugreek seeds, followed by ajwain, hing and curry leaves.Take care not to burn methi and ajwain.
Next add garlic and saute till they change color a bit and nice aroma of sauteed garlic emanates.
Add chopped pumpkin and chopped tomatoes to this and saute till tomatoes release oil. Add sambhar powder to this and mix well. (The secret to the color)
Saute for 2 minutes, add tamarind water, and mix well. Let this cook in a medium flame for 10 -15 minutes, after which the pumpkin must be 3/4th cooked, add salt now and mix well.
Let this be on the stove until the kuzhambhu thickens and oil releases on top. Take it of the stove. Serve hot with Rice and Pappad for an wholesome meal.