Ingredients
3 russet potatoes (about 1 1/2 pounds total)
Vegetable oil, for frying
1 bunch fresh rosemary
Kosher salt
Preparation
Peel potatoes and slice lengthwise into 1/8-inch planks, then cut lengthwise into 1/8-inch juliennes (or use a Japanese mandoline fitted with the julienne blade). Immediately submerge in a bowl of cool water; let stand 10 minutes. Drain; lightly press potatoes between paper towels or clean kitchen towels to dry completely.
Fill a heavy pot with about 1 1/2 inches oil (it should come no more than a third of the way up sides of pot). Heat over medium-high until a deep-fry thermometer reaches 365 degrees.
Carefully add rosemary sprigs to oil and immediately cover pot with a splatter screen or lid for a few seconds to prevent splattering; remove screen when popping sounds subside. Fry until darkened slightly and bubbles surrounding sprigs begin to subside, about 30 seconds. Transfer to a paper towel-lined tray; season with salt.
Return oil to 365 degrees and fry potatoes, a handful at a time, until crisp and just beginning to turn golden, about 2 minutes per batch (returning oil to 365 degrees between each batch). Transfer to paper towels; season with salt. Toss fries with rosemary to combine; serve.
