Peel the potatoes and shred them on a mandoline or grater. Place the shredded potatoes in a large bowl and rinse under cool running water to remove excess starch until the water runs clear, then drain and squeeze out the excess moisture.
In a large bowl, combine the potatoes, leeks and egg. Then sprinkle on the flour, 1 tablespoon Khmeli Sunel and salt, and stir to combine.
Preheat a large, non-stick saute pan over medium heat. Add 1 cup of the potato mixture to the pan and flatten into a pancake, approximately 1/2" thick. Cook 3-4 minutes until the pancake begins to solidify and turn golden. Carefully flip and allow the second side to firm up as well, cooking 3-4 minutes more.
Carefully slide the pancake onto a board and and allow to cool slightly. Cut into wedges and keep warm until the remaining pancakes are cooked.
Stir the remaining 1 teaspoon Khmeli Suneli into the sour cream and serve alongside warm pancakes.