2 medium Yukon gold potatoes (about 10 ounces), scrubbed
1 large parsnip, (about 5 ounces)
2 scallions (white and green), chopped
2 tablespoons minced flat-leaf parsley
1/2 teaspoon kosher salt
Freshly ground black pepper
1 tablespoon extra-virgin olive oil
Grate the potatoes, skin on, into a large mixing basin. Peel and grate the parsnip before mixing it in with the potatoes. Toss the vegetables with the scallions and parsley, then season to taste with salt and pepper.
Brush half of the oil into a large (12-inch) nonstick skillet and heat over medium heat. Add the potato mixture and press lightly with a spatula to produce an even cake. Cook, stirring the pan occasionally to prevent sticking, for about 10 minutes, or until the hash browns are crisp and brown.
Remove the skillet from the heat and set a flat plate on top of it. Flip the pan carefully onto the platter to release the potato cake. Return the hash browns to the skillet after brushing the griddle with the remaining olive oil. Cook for another 10 minutes, or until browned and crisp. Remove from the skillet and place on a warm serving platter. To serve, cut into wedges.