In a medium pot, pour enough oil so that the oil comes 3 inches up the sides. Heat over medium heat until a deep-frying
thermometer inserted in the oil reaches 350 degrees F. (If you don't have a thermometer, a cube
of bread will brown in about 3 minutes.)
Slice the potatoes thinly on a mandoline
. As you slice them, put them in a bowl of cold water to cover.
the potatoes and pat dry. Working in batches if necessary, cook the potatoes in the oil until they are golden brown and crispy, about 3 minutes. Add the garlic if using, along with the potatoes. Remove the potatoes from the oil to a large paper towel-lined bowl and season them with the rosemary and salt, shaking the bowl to distribute the seasonings evenly.
Cook's Note: Rosemary on potatoes is so good, and hot crispy chips
with rosemary and some sea salt are the best. I think of sea salt the way I do extra-virgin olive oil
, as something to finish with. I use Maldon Sea Salt
, which has a nice flaky