This recipe took me so many tries to nail down--let me share! These deep fried sweet potato fries have an amazing crunch while retaining the fluffy sweet potato centers you will love.
Wash, peel (optional), and cut into 1/2" or 1/4" matchstick shape fries. 1/2" (preferred) will require par-cooking.
Rinse under running water, drain and repeat once more. Dry in salad spinner or with towels.
To par-cook: boil in water until tender, and just cooked all the way through, not mushy and breaking in our hands. About 8-15 minutes.
Cooking
Make some batter. About 4 parts cornstarch to 3 or 4 parts water until milky, but not too watery.
Dip fries (I do about 5 so they don't sit there as the cornstarch gunks up). Shake off excess.
Quickly drop into the fryer 1 at a time so they don't stick. About 1-2 minutes at 325-350 °F. We don't want it to brown too much yet.
Remove from oil, rest on paper towels to remove oil and cool off.
Repeat to finish all the fries, making sure you mix up the batter before each small batch (For me, each set of 5 fries). You might have to add some water if the batter is sludgy.
So after the first batch, they're pretty good now, but you have to eat them quickly or they lose the crunch. I have discovered that a 2nd dip & fry makes the crunch better and last much longer.
Dip + fry a 2nd time, following the same steps. Except this time you can leave them in the oil until the fries brown enough to your liking. It still should be around 1-2 minutes. Season each batch while hot. I like salt, paprika, and finely (freshly) ground pepper.