You could toss the potato slices in some oil (the 2 tbsp) & salt and bake them in an oven until browned or pan fry them in a wide pan as a single layer until lightly browned. Flip over and cook the other side as well. I had to do 2 batches to finish all the potatoes. Remove them and keep aside.
Meanwhile grind coriander leaves, green chillies, garlic & ginger to a slightly coarse paste.
Heat a tsp of oil in the same pan and add cumin seeds, then add the ground coriander paste and cook this for a few minutes (so the raw smell goes away). Rinse the jar of the mixie with a few tbsp of water and add this to the fried paste and a bit of salt to taste.
Toss in the potatoes at this juncture and stir gently (with a spatula) so they are coated with the coriander masala. Keep the flame on a medium high until all the water is absorbed, which only takes a few minutes.
After that, reduce the flame to medium and keep tossing the potatoes until browned and dry. Serve with rice and rasam or my favorite combination curd rice and this - bliss.