Place the chopped parsley, cilantro, dill, and leek in a large bowl. Add in the eggs, followed by salt, pepper, and turmeric. Mix to combine, and make sure all the ingredients are sticking together. If the mixture isn't sticking together, add another egg.
If desired, add in the chopped walnuts and barberries and give it a stir.
Heat 3 tablespoons olive oil in a large (10 to 12 inches) nonstick pan over medium high heat. Once the oil is hot, transfer the kuku batter into the pan and spread evenly using a spoon or rubber spatula.
Place a few pieces of kitchen paper towel on the pan and top with the lid. Let it cook undisturbed for 10 minutes.
Remove the lid and paper towel, and check to see if the surface of the kuku is dry. If so, carefully place a large plate on the pan and flip the kuku.
Add 1 tbsp oil to the pan. Transfer the kuku to the pan and cook on the other side for another 10-15 minutes. There is no need to cover the pan.
Transfer to a serving plate and slice before serving.