Prepare the Potatoes: Cut peeled potatoes into large rectangles.
Slice them lengthwise into uniform 0. 25-inch / 0. 6 cm thick slices.
Soak to Remove Starch: Rinse the slices in cold water, then place them in a bowl of ice-cold water to soak for at least 20 minutes. This is key for crispiness!
Mix the Spices: While potatoes soak, combine the sesame, cumin, coriander, and fennel seeds in a shallow dish.
Set aside.
First Fry (Blanching): Drain the potatoes and pat them completely dry.
Heat oil to 340°F / 170°C.
Fry in small batches for 6-7 minutes until cooked through and blistered, but not browned.
Cool and Coat: Transfer potatoes to a paper towel to drain and cool for at least 5 minutes.
Once cool, press each slice firmly into the seed mixture to coat, shaking off any excess.
Second Fry (Crisping): Increase oil temperature to 375°F / 190°C.
Fry the coated potatoes again, in batches, until golden brown and wonderfully crisp.
Season and Serve: Drain on paper towels.
While still hot, sprinkle with salt. Just before serving, drizzle with fresh lime or lemon juice for a zesty kick.
Don't Skip the Soak: Soaking in ice water for 20+ minutes removes excess surface starch, preventing the potatoes from burning before they are fully cooked and crisp.
Dry, Dry, Dry: Moisture is the enemy of crispy!
Pat the potato slices completely dry before their first fry. Water will cause dangerous splattering and result in soggy potatoes.