Preheat oven to 425°F with rack in centre of oven.
Cut fingerling potatoes in half lengthwise. Place into a large bowl. Add olive oil, enough to coat each potato. Toss well. Add a generous sprinkling of kosher salt and some freshly ground pepper. Toss again.
Spread potatoes evenly on a baking sheet, trying to get an even layer with little overlap (reserve the oily bowl for later!). Bake for 15 minutes. Remove from oven, stir and return to the oven for another 15 minutes.
Meanwhile, grate your Parmesan or Pecorino. Remove the fries from the oven (leaving the oven oand return to the oily bowl. Sprinkle with Parmesan cheese and toss (if using minced garlic, add now as well). Return the fries to the baking sheet and bake a further 8-10 minutes, until the Parmesan is browned and crispy.
To serve, sprinkle with chopped chives (or parsleand optionally, a squeeze of fresh lemon.
Notes
Be sure to read the notes above this Recipe Card, for more tips, options, substitutions and variations for this recipe!