Place the potato and enough water to cover it in a medium sized sauce pan, cover and cook until the potato has softened, about 15 minutes.
Once cooled, peel, grate and set aside in a medium sized mixing bowl.
Place the walnuts in a food processor and pulse until finely ground. Take extra care to not over process them. Remove and add to the mixing bowl.
Place the fresh herbs in the same food processor and pulse until you have a finely chopped mixture of herbs. Remove and add to the mixing bowl.
Add the remaining ingredients to the mixing bowl and mix well.
Select a medium sized pan, add 4 tablespoons of oil and heat over medium heat until the oil begins to shimmer.
Pour the entire Kuku mixture into the pan and shake until the mixture has spread and has an even smooth surface.
Cover, reduce the flame to medium low and cook for 15 minutes.
After 15 minutes, the Kuku mixture should have firmed up enough to be flipped over. The easiest way to do this is to cut the Kuku in quarters and flip each piece individually. If you would like to keep the Kuku whole, however, you can place a plate large enough to cover the pan and carefully flip the Kuku onto the plate. Once flipped, you can slide the Kuku back into the pan.
Add the remaining 2 tablespoons of oil to side of the pan and shake the Kuku around so that the oil spreads underneath it.
Cook uncovered for 10 minutes.
Remove the Kuku from the pan and serve with Persian flat breads, fresh herbs and a side of yogurt.