Here, as promised, is the recipe for sweet potato planks with basil aoili. But first, a confession: I have never made sweet potato planks with basil aoili. It remains strictly the domain of my man-friend, Thomas. Thus, the recipe bellow is written in minute, somewhat pretentious detail (apologies for that) by him, and I can take no credit for any successes or failures you may have with it. Although I am quite certain I could make sweet potato planks with basil aoili, and indeed have often aided him in the process of doing so, it is indisputably one of those recipes that always tastes best when someone else makes it for you.
If you've never made real aoili before, I thoroughly recommend you try it. It's not that hard (just be very, very patient when adding the first few drops of oil) and is so much more delicious than anything commercially available.
Tom's Sweet Potato Planks with Basil AioliAs Julia doesn’t dabble in the dark arts of sweet potato and aioli, she felt it would be better if I enlighten you on the subject. So here, by popular request, is the recipe:
Cut two medium sweet potatoes into chunky plank-like chips (2-3cm fat, and as long as possible). Make them slightly fatter than you would think, they seem to shrink in the oven.
Toss the planks in a small drizzle of olive oil and arrange on an oven shelf or baking dish – make sure it’s non stick/baking paper lined if using a tray of any kind. Throw a few garlic cloves in as well (not peeled) with just their bottoms chopped off.
Bake at around 220 ºC until browned on all sides. You may have to tun them at some stage if you’re not cooking on the oven shelf. (Note: while cooking the chips directly on the oven shelf may result in more evenly browned chips, it may also result in a sticky, sweet-potato-y residue that is difficult to clean. If you don’t like cleaning, go with the baking paper or non-stick tray.) Smaller chips may become slightly burnt but are still quite delicious. If you don’t end up with nicely coloured chips that’s ok too, they’ll still be delicious. Also, make sure you take the garlic out when it’s soft – don’t burn it. But don’t open the oven too much or the chips won’t get hot enough to crisp up.
Now you can whip up your aioli. Pop one egg yolk into the milkshake cup of a stick mixer* along with the squeezed out pulp of the roasted garlic cloves, a splash of lemon juice, and a dessertspoon or so of water. You want this mixture to be able to engage with the blades of the stick blender.
With the blender on and engaged with the aforementioned mixture, VERY gradually (drop by drop) add approximately one cup of oil, using half good quality extra virgin olive oil, and half a more innocuous oil such as light olive, canola, sunflower or vegetable (you can experiment with quantities but the more rich the oil, the richer the aioli will be). You want the mixture to thicken to the consistency you would expect from a good quality mayonnaise. You can probably make around a cup of aioli from one egg yolk. If the mixture starts to separate (you will know), stop immediately and transfer to another container**. You are either mixing too fast, or you have added too much oil. Don’t beat yourself up about it though, as the more mistakes you make, the better aioli maker you will become.
At this point you can either taste and add more lemon juice or garlic (you can use fresh for a more aggressive garlicy-ness, or add more roasted for a softer, more evocative warmth on the palette), or upgrade your aioli into a basil aioli by stirring through a mixture of a handful of basil, a splash of extra virgin, and half a clove of fresh garlic that has been either pounded in a mortar and pestle (the best way) or blended. I find the basil really complements the sweet potato taste. You could even use purple basil if you are an aesthete.
Serve the planks generously sprinkled with salt flakes (I recommend Maldon) and cracked pepper, and a large amount of aioli for dipping.
*It is also possible to produce aioli with any other kind of beating device/implement, such as a food processor. I, however find that a stick blender is generally less likely to fail.
If one wishes to be a historical purist, it is also possible to conceive aioli in a mortar and pestle with the simple addition of a garlic clove. Just bash up the clove and, drop by drop, bash in the oil (in the mortar and pestle). This requires great patience but results in a fair amount of status within the aioli community, and smug desire to turn one’s nose up at those who require the use of egg or electricity to produce their aioli. You can also use this method to ‘rescue’ you separated aioli if you’re out of eggs. Just begin the new aioli in this way, then transfer the new mixture to another vessel and gradually blend in the separated mixture.
**If splitting occurs, it can either be cured using the mortar and pestle method mentioned above, or by simply adding a few drops of boiling water and blending rapidly.