Lightly scrape the bitter gourds on the outside and slit it length wise from the center keeping the base intact.
Now generously apply salt inside and outside of bitter gourds .
Collect the peels in a bowl and apply salt (use of peels is optional but I prefer to use peel in the stuffing). Then keep aside for minimum of 30 minutes..
Now wash the karela and peels 2-3 times with enough water and squeeze properly.
If you are in a hurry then boil them in slightly salted water for 3 - 4 minutes, drain and squeeze well.
Take a bowl add all the spices,washed and squeezed peels and 2 tsp oil and mix it well.
Stuff the masala mix in all the bitter gourds, and press the masala mix tightly with your thumb so it will not come out while cooking.
If you still have some masala mix left, then slice the potatoes in thick roundels, slit them from the center to make pockets and stuff the masala in it, or stuff the masala mix in some thick green chilies.
Heat about 5 tbsp oil in a thick bottom pan, and add a pinch of turmeric then add place stuffed bitter gourds (and potatoes and chillies if any) in the pan.
Cover the pan and cook on slow flame. Keep turning the sides occasionally, so they can cook from all the sides. (It will take a minimum 15- 20 minutes to cook properly)
When done take out in a bowl and serve.
It will remain fresh for minimum 3 days at room temperature.