Step 1Place the potatoes, water and salt in a large, heavy bottom saucepan. Bring the water to a boil over high heat, about 10 minutes. Reduce the heat to a simmer and cook the potatoes until they are just tender when pierced with a knife, 15 to 20 minutes more.
Step 2Drain the potatoes and set aside until cool enough to handle. (The recipe can be prepared to this point up to three days in advance; refrigerate the potatoes until needed, then continue with the recipe.)
Step 3Using a fork, gently smash the potatoes. The thicker the smashed potatoes, the fluffier the fries; conversely, the flatter the potatoes, the more crisp the fries. Set the smashed potatoes aside while you heat the oil.
Step 4Fill a heavy-bottom deep saute pan with oil so the oil comes up the sides of the pan by one-half inch. Heat the oil to a temperature of 350 degrees; the oil will shimmer in the pan.
Step 5Fry the potatoes in the oil until crisp and golden, about 2 minutes, careful not to crowd the potatoes (fry a single layer of potatoes at a time; this will need to be done in batches). Drain the potatoes on a rack until all of the potatoes are fried.
Step 6Season the smashed fries with additional salt to taste, and serve immediately.