Wash the ridge gourd, slightly peel them retaining the remaining veggie to use in some other dishes.
Cook the peel until soft with little water , haldi and green chilli. It will get cooked easily.Once cooked allow it to cool .Don't throw away water.
Meanwhile take a kadai / frying pan. Add urad dal, chana dal, red chillies ,curry leaves and hing. Fry them in oil till urad dal n chana dal turns golden brown in color.
Add grated coconut to it and roast for a min.Switch off and allow to cool.
Transfer roasted masala to a blender / mixer. Add salt , tamarind , jaggery (optional) and cooked ridgegourd peels. Grind adding little water. Don't make the chutney too smooth, a bit of coarseness gives it nice texture.
Prepare a tempering by heating 1 tsp oil and adding mustard seeds and curry leaves.
Garnish chutney with tempering. Now ridge gourd peel chutney is ready to serve. Enjoy it with plain hot steamed rice drizzle with coconut oil/ghee or serve with idli ,dosa,etc.
Variation :Instead of ridge gourd peel, you can use bottle gourd peel / snake gourd peel / Chayote squash peel / sambar cucumber peel etc.