Rinse cut baking potatoes (such as Idaho or russet) in three changes of cold water, then soak in ice water.

In a deep fryer, pour in oil to a depth of 3 inches. Heat to 325°F.

Drain potatoes and dry well. Fry in batches (do not crowd) until just beginning to brown, about 10 min. Remove and drain on paper towels or in a paper bag (they'll be soggy; don't worry).

Fry potatoes again in batches until brown and crisp, about 2 min. Remove and drain on paper towels or in a paper bag. Season with salt and serve immediately.