In South Africa, we get a variant of the normal french fries or fries people over the world are used to. We call them slaptjips or slapchips. The literal translation means something to slack or weak chips. Fries around the world is crispy and soft on the inside, slap tjips are not crispy but soft. We douse and soak them in vinegar. I don't know if this is a thing overseas, but when I had fish and chips in the UK the fries were crispy. Fish and chips here in South Africa (Cape Town) our chips are drenched in loads of vinegar. This is not the healthiest of foods as you can presume. So, I make South African sweet potato fries that uses only healthy ingredients! But, again, as I have stated in previous posts, what is healthy is up to you and not anyone else. If you feel fine with eating chocolates don't let someone stop you! Okay, chocolates are probably not healthy (that is if you eat those that are more sugar than cacao). In any case, this is how I make slap tjips with sweet potatoes! (For those who have tried to make crispy sweet potato fries, try this recipe. It is not 100% crispy (it is, after all, a slap tjips recipe) but some of the edged get really crispy. See the post below for my best-educated guess to why.)
Firstly, and obviously, cut the sweet potatoes into fries. They lose almost two-thirds of their size, so cut them relatively thick.
Lay them on a baking sheet. I am not too worried about them touching, even though I know some people swear by placing them in neat rows. I do not have the time and patience.
I then put some oil on them (I use rendered animal fat for this, as it gives a superior taste). And some salt and pepper.
Place them in a hot oven, I do mine at 260C. I know this is hot, so please keep an eye on them! It takes roughly 10-20 minutes. Everyone's oven is different, you know your oven's strength! The key is to keep an eye on them!!!
(These are almost done. See the image below for an important last step.)
The last step which gives you some crunchy texture on some of the fries is simply to leave them in the oven when you turned the oven OFF for 5ish minutes. I find that leaving them in the oven, in some sense, dehydrates some of the edges. This makes for an awesomely crunchy texture. And you don't need other ingredients like cornstarch or a batter of some kind.
These make for an awesome side dish, or simply to snack on. They are intensely sweet (you after all reduced them by two-thirds and they are called sweet potatoes!). Please give them a try and if someone ever complains to you that your sweet potato fries are not crispy, tell them it is a variant of South African slap tjips and that they are meant to be like that!