Heat 2 tablespoons olive oil in a 10” skillet over medium heat. Add the leeks and bell pepper and season lightly with salt and pepper. Cook, stirring frequently, until softened and golden, about 6 to 8 minutes. Transfer to a large bowl and set aside. Wipe the skillet clean with paper towel.

Grate the potatoes and firmly squeeze as much liquid out of them as possible (the drier the potato, the crispier the result). Mix the grated potatoes with the leek mixture. Season with parsley flakes, salt, and pepper and toss well.

Heat 1 tablespoon olive oil in the skillet over medium heat. Add the potato mixture and press down firmly with a spatula. Cook, shaking the skillet occasionally, until the latke is a deep golden brown, about 10 minutes. Gently loosen the edges and slide the latke onto a large plate.

Heat the remaining tablespoon of olive oil in the skillet. Place another plate onto the latke and flip, so the cooked side is facing up. Slide the latke back into the skillet and cook another 10 minutes, or until it is a deep golden brown.

Transfer to a platter and allow to cool for 3-4 minutes before garnishing with a dollop of sour cream and chopped cilantro. Serve immediately.