Peel the potatoes and cut them into thin sticks. 

I used a mandoline that can also make regular thickness fries and very thin fries like these. Be careful with your fingers and preferably use a cutting glove.

Now it's about getting some of the starch out of the potatoes. 

Place your sticks in a bowl and fill it with lukewarm water.

Drain the water and repeat the process twice. Finally, the water is almost clear, and the potatoes are ready.

Bring water and vinegar to a boil. Add the potatoes and boil them for 3-4 minutes.

Take them out of the water and place them on a tea towel so they can dry and cool. If you have the opportunity for a short trip in the freezer, it would be an advantage.

Heat neutral oil in either a pot or deep fryer. The temperature should be approximately 170-175 degrees Celsius (338-347 degrees Fahrenheit).

Fry the potatoes until it stops sizzling around them. It took a few minutes for me. Be careful not to put too many potatoes in the oil at once, as they lower the oil temperature.

Take them out of the oil and place them on absorbent paper (clean tea towel/kitchen paper). Let them cool for 5-10 minutes. If you have a freezer/fridge nearby, place them in it. It might also be cold outside, which is also an advantage.

Put them back in the oil until they turn golden around the edges. 

Take them out and let them drain on absorbent paper. 

If you are making a large batch, you can place them in an ovenproof dish in the oven at 80 degrees conventional oven while you make the rest, so they remain crispy.

Sprinkle salt on and your crispy potato sticks are ready to serve.