Heat oil in a pan and add mustard seeds. Let it splutter and than add green chillies
Finely chop onion and add into the pan, saute till it turns brown and add ginger garlic paste. when the raw smell goes away add poppy seed.
Next add pumpkin , salt and mix it well. cover till it turn soft.
Make a tamarind and jaggery mixture with some water and add 2-3 tsp into the curry.
You can add the tamarind water as per taste.
Add some more if you want , garnish with coriander leaves and serve hot.