To prepare peerkangai thogayal, slice off the top and tail end of the ridge gourd and cut into thin slices~1/2 cm thick. Heat 1 tsp oil in a large sized pan and saute the gourd slices with a pinch of turmeric for 4-5 minutes on a high flame. Remove this into a dish and allow to cool.
In the same pan, heat the oil. Add the mustard seeds, red chillies, urad dal and fry on a medium flame until the dal turns golden.
In a mixer jar, take the sauteed ridge gourd slices and the fried dal-red chilli -mustard seeds mix, coconut, tamarind, asafoetida water, salt and grind to a fine paste. Remove this into a serving bowl
Heat the 1 tsp oil in the same pan. Add the mustard seeds, red chili, urad dal and curry leaves and fry until the dal is golden and crunchy. Transfer this over the thogayal.
Serve this with hot rice, ghee / gingelly oil and a dry vegetable curry like cabbage or carrot on the side.