Slice potatoes into fries using your mandoline on the julienne setting or using this handy dandy fry slicer (we received this as a wedding gift lol). You can also just slice the potatoes into fries using a knife. Obviously, this will take much longer. Just try your hardest to cut evenly shaped fries. Otherwise they will cook differently.
Soak potatoes in cold water for 1 hour. Drain then pat until VERY VERY (VERY) DRY. Wet fries into hot oil = BAD. Why soak? Soaking will get rid of excess starch and result in crispier fries. SCORE.
Using a deep fryer or cast iron pot with an oil thermometer, heat canola oil to 325F. Fry the fries in small batches (like 3-4) for about 2 minutes – fries will be partially cooked but not browned. Remove from oil and drain. I found the best way to “drain” the fries was to place then on a cooling rack with a cook sheet lined with paper towel below. Continue until all the fries have been fried once. Though, you’ll likely have to wait between batches to allow the oil to come back up to temperature.
Heat canola oil to 375F. Fry fries for a second time, in small batches for about 2-3 minutes. Basically until the fries are crispy enough for your liking. Remove and drain like in step 3. Continue until all the fries have been fried twice. Again, you’ll likely have to wait between batches to allow the oil to come back up to temperature.
Place all the fried fries in a large bowl, mix in truffle oil, truffle salt, garlic powder, and rosemary until fries are completely coated. I recommend starting with a little of each ingredient, mixing to coat the fries then tasting a fry to see what more (if anything) should be added.
Devour by yourself or share with friends whom will now love you FOREVER.