Wash potatoes well and slice in half lengthwise leaving the skin on, then slice again, and again as needed to create evenly-sized fries. It is important that the fries be similar to each other in size and thickness so that they cook evenly.

Place sliced potatoes in a large bowl of ice water and allow to soak for 30 minutes to 1 hour, which will help some of the excess starch to leech out of the fries. Drain well and pat completely dry on paper towels. This process of soaking and drying will help the potatoes crisp better in the oven.

Preheat the oven to 450 degrees. Pour 2 tablespoons of the olive oil onto a baking sheet and place in the oven to get hot. While the pan and oil are heating, drizzle the dried potato slices with the remaining 4 tablespoons of olive oil and season with salt and pepper.

Remove hot pan from the oven just before the oil starts smoking and carefully arrange the fries in a single layer. Return the pan to the oven and bake for 30-35 minutes, turning the fries with a metal spatula once at the 20 minute mark.

Once the fries are soft on the inside and crispy and browned on the outside, remove from oven and pile onto a serving plate. Drizzle with the juice of ½ of the lemon, then sprinkle with the oregano, garlic, parsley (if desired) and feta cheese. Slice the remaining ½ of the lemon into wedges and use them to garnish the serving plate. Adjust salt if necessary, but remember that the feta itself is quite salty so in all likelihood you won't need to add any salt.

Serve immediately, family style.