Wash and pat dry the ridge gourd and cut it into manageable 2-3 inch pieces
With a peeler remove the spiny fibrous ridges, these are inedible. Discard them.
The smoother green skin that remains is edible. Using a knife chop if the skin and set aside to use. the soft white inner core can be used for curries or stirfries.
Finely chop this part of the peel and set aside for cooking
To make the sabji
In a pan add the oil and set to medium heat.
When the oil warms up add the mustard seeds, cumin seeds and red chillies. Saute till the mustard splutters.
Add the chopped ridge gourd peels and the curry leaves with salt, turmeric, and tamarind paste.
Mix well to saute for a minute and then cover and cook for 4-5 minutes
Open and mix well again and add the jaggery and the coconut and saute till it is well incorporated and cooked.
Taste test for the sweet and sour balance.
The dish is ready to serve.
Notes
You can add 1/2 tsp of red chilli powder along with the turmeric and salt if you like it spicy.