To cut the karelas, first peel the skin using a peeler. Don't discard the skin. Leave it in the bowl in which you are going to salt the karelas. Then cut them in round shape and sprinkle a little bit of salt all over them. Let it sit for a couple of hours.
Wash the salted karelas so that there won't be excess salt and set aside. Make sure all the water is drained. In a kadhai, add oil and shallow fry them or you can make them without frying as well, like I did.
Take them out of the kadhai and put it in a plate, if frying. In the same kadhai, add the onion and potatoes and sautee them for a few minutes.
After the potatoes are half cooked, add the washed karelas along with the peel.
Add salt, turmeric, red chilli, garam masala. Stir for a couple of minutes then cover the kadhai and cook for a few minutes
Sautee for 10 mins and check, you will that that the karela has changed color from light green to a bit darker.
Add amchoor powder and mix it. Let it simmer and sautee for additional few mins.
You can garnish with cilantro and serve it with paratha, roti along with raita