In a bowl, mix all the ground spices. Keep ready.
Peel the potatoes. Grate the potatoes using thick side of the box grater. Rinse the potatoes 2-3 times to get rid of excess starch.
Soak the potatoes in water mixed with salt & turmeric for 30 minutes. This removes more starch.
Drain and spread the grated potatoes on a cloth/kitchen towel. Pat them dry completely.
Set oil for deep frying on stove to heat up. Dont use a lot of oil (2-3 inches oil is enough) and use a deep pot/kadai for deep frying.
Add the potatoes to a wide plate/large bowl. Add the cornstarch and toss with the potatoes lightly.
Deep fry the potatoes on medium hight heat in small batches in hot oil until golden and crisp.. Drain on a paper towel.
Let the fried potatoes completely cool down.
In the same oil fry peanuts and cashews (if using raw), curry leaves and dried red chilli.
Add on top of potatoes. Sprinkle 2 tablespoon masala or more/less as you like. Gently mix everything together without squeezing till everything coated well.
Store in a air tight container for 2-3 weeks.