Start by cutting your baking potatoes into fries. At our place, there's not always consensus on whether they should be thin or thick, so I typically make both.

Cut off the ends of the baking potato lengthwise and cut it in half. Now you have the option to cut them into thick slices about 1-1.5 cm thick/wide. The parts you've cut from the ends can be sliced into thin fries. That way you get the best of both worlds. However, the thin ones can't be cooked sous vide first; they need to be boiled in water with vinegar for about 5-10 minutes. Check out this recipe for French fries for more details.

Place the potato pieces in a bowl with lukewarm water for 1 minute. Drain the bowl and refill it with lukewarm water. Drain and repeat. By now, the water should be almost clear, meaning most of the starch has been drawn out of your fries.

Add salt and distribute it well using your hands.

Place the fries in a vacuum bag in a single layer. I used two bags to fit them all.

Cook them sous vide for 30 minutes at 85 degrees Celsius (185 degrees Fahrenheit).

Carefully take the potatoes out of the vacuum bag and place them on a rack with a kitchen towel underneath. They need to cool down and dry. If you have space, put them in the freezer for 20-30 minutes.

Heat your (deep fryer) to 140-150 degrees Celsius (284-302 degrees Fahrenheit) and cook the fries for 5 minutes. Don't put too many in the fryer at once, as the temperature will drop too much. I fried them in two batches.

Place them on a rack with a clean kitchen towel underneath. Dab off the excess oil on top with a kitchen towel and let them cool slightly. Now put them in the freezer, usually I do this by laying them in a single layer on a clean kitchen towel. If I have a lot, I'll add another layer on top with a kitchen towel over it.

They just need to get completely cold now and then can be packed into portion sizes in the freezer so you can easily have homemade fries whenever you want. They just need to be cooked directly from the freezer.

Take the ice-cold fries directly from the freezer and into 190-degree hot oil until they turn golden and crispy. This typically takes 6 minutes.

Let them drain on a rack, dab off the excess oil on top, and season with salt.

Serve immediately piping hot.