Peel potatoes and place them, whole, in a bowl of cool water to prevent browning. Use a sharp knife or a crinkle cut knife to cut the potatoes into ½- by ½- by 2 ½-inch batons.

Fill a medium pot of water, add the kosher salt and the potatoes, and bring to a gentle simmer. Cook potatoes until you can pierce one with a knife with little resistance, 10–12 minutes. Use a slotted spoon or spider strainer to carefully transfer them to a plate to cool to room temperature.

Pour oil into a large Dutch oven or deep-fat fryer and heat oil to 250°. Fry the potatoes, in two batches, until they are slightly colored and have developed a thin crust, 5–6 minutes. Use a slotted spoon or spider strainer to transfer them from the oil and to a paper-lined plate to drain.

Heat the oil to 370° and fry the potatoes until they are golden brown and crispy, 5–6 minutes. Use a slotted spoon or spider strainer to transfer them from the oil and to a paper-lined plate to drain. Season with sea salt and pepper and serve with aioli.

Mince garlic with salt until you have a rough paste. Add garlic paste and egg yolks to the bowl of a food processor and blend on high for 20 seconds. Add malt vinegar and mustard, then blend for another 20 seconds. Scrape down the sides of the bowl.

Combine the canola and olive oil together in a measuring cup. Turn the food processor on and slowly add the blended oil in tiny drops until about one-quarter of the oil has been added. Continue to add the remaining oil slowly in a very thin stream. When all the oil has been added, scrape down the sides of the bowl and process for an extra 10 seconds. Season to taste with salt.