Heat pan adding oil and bottlegourd peel. In medium flame roast the peels until they wilt and shrink. Transfer them to a plate. Next to the same pan add rest of the oil, chickpea lentils, blackgram lentils, coriander seeds and curry leaves.
Stirring constantly roast the lentils till they turn little brown. Next throw in grated coconut and green chillies also to the pan. Continue roasting for few more seconds.
Next transfer all the roasted ingredients in to a mixer jar. Add tamarind, jaggery, asafoetida, salt and some water. Grind them all together to fine paste.
Heat a tempering pan and add all the ingredients under "To temper" list, when mustard seeds crackle pour it over the chutney. Bottle gourd peel chutney is ready.