Preheat oven to 400 degrees F . Line two baking sheets with foil.
Cut sweet potatoes lengthwise into 1/2-inch thick strips. Place sweet potatoes in a large bowl. Drizzle with oil and toss to coat. Arrange sweet potatoes in a single layer on prepared baking sheets and bake for 10 to 15 minutes.
Turn potatoes over and bake for 10 to 15 minutes more or until golden brown. Season to taste with salt and pepper. Sprinkle with parsley if desired.