Published November 1, 2010. From Cook's Illustrated.
For our roasted smashed potatoes recipe, we chose Red Bliss potatoes for their moist texture and thin skin. Parcooking the potatoes on a baking sheet covered in foil on the oven’s bottom rack, with a splash of water in the pan, gave us creamy flesh that tasted sweet, deep, and earthy. Letting the hot potatoes rest after they parcooked meant they wouldn’t crumble apart when smashed, and drizzling the potatoes with olive oil before and after smashing them ensured that the oil reached every nook and cranny. And finally, using another baking sheet balanced on top of the parcooked potatoes to smash them gave us perfect cracked patties in one fell swoop.
This recipe is designed to work with potatoes 1½ to 2 inches in diameter; do not use potatoes any larger. It is important to thoroughly cook the potatoes so that they will smash easily. Remove the potatoes from the baking sheet as soon as they are done browning—they will toughen if left too long. A potato masher can also be used to “smash” the potatoes.
1. Adjust oven racks to top and bottom positions and heat oven to 500 degrees. Arrange potatoes on rimmed baking sheet, pour ¾ cup water into baking sheet, and wrap tightly with aluminum foil. Cook on bottom rack until paring knife or skewer slips in and out of potatoes easily (poke through foil to test), 25 to 30 minutes. Remove foil and cool 10 minutes. If any water remains on baking sheet, blot dry with paper towel.
2. Drizzle 3 tablespoons oil over potatoes and roll to coat. Space potatoes evenly on baking sheet and place second baking sheet on top; press down firmly on baking sheet, flattening potatoes until 1/3 to 1/2 inch thick. Sprinkle with thyme leaves and season generously with salt and pepper; drizzle evenly with remaining 3 tablespoons oil. Roast potatoes on top rack 15 minutes. Transfer potatoes to bottom rack and continue to roast until well browned, 20 to 30 minutes longer. Serve immediately.