adapted by There's Always Thyme to Cook
Source: Serious Eats
http://www.seriouseats.com/recipes/2011/11/ultra-crispy-roast-potatoes-recipe.html
4-5 large russet or Yukon gold potatoes, rinsed well, and cut into 2-inch chunks (peeled if you like)
1 tablespoon white vinegar
1/4 cup olive oil
coarse salt and freshly ground black pepper
1 teaspoon dried thyme or 8-10 sprigs fresh
Preheat oven to 500°F. Place potatoes in a large microwave-safe bowl and add cold water to cover by at least an inch. Add salt, about a tablespoon, and the vinegar. Cover with a vented lid and microwave on high for about 15 minutes. Be careful with the hot water and steam from the bowl. Potatoes should show a slight resistance when poked with a paring knife or fork. If not, microwave another 5-10 minutes. Drain potatoes.
Add olive oil to bowl with potatoes. Season with pepper and more salt (to taste) then toss with a large spoon until exteriors are slightly scratched up and coated in a thin layer of oil-potato mix. Spread potatoes in one layer on a heavy rimmed baking sheet. Use two baking sheets if necessary. Sprinkle the thyme or thyme sprigs over the potatoes.
Place baking sheet in the oven and roast until the bottoms of the potatoes are very crisp and golden brown, about 20 - 25 minutes. Using a thin metal or nylon spatula, flip the potatoes and roast until the the other side is golden brown, another 15 to 20 minutes. Serve immediately. If using fresh thyme sprigs discard before serving.
Note: Instead of microwaving, you can par-boil the potatoes on top of the stove if you prefer. Bring to a boil and simmer until the potatoes have a slight resistance when poked with a paring knife or fork.