Step 1: Cut and Soak: Cut the potatoes, skin on, into 1cm-thick sticks (uniform thickness cooks evenly). Soak them in cold water for 20 minutes to rinse off surface starch — less starch means crisper, less sticking — then lift them out and pat completely dry with paper towels.
Step 2: Toss With Oil and Spices: In a large bowl, whisk the olive oil with the paprika, garlic powder, and black pepper. Add the potato sticks and toss by hand until every stick wears a thin, even coat. Oil is the crisp-shell medium, but don't overdo it or they go soft.
Step 3: Load the Basket: Spread the sticks in a single layer with no overlap (overlap means steam, not crisp). Set the air fryer to 200°C (400°F) for 18 minutes.
Step 4: Shake at the Halfway Mark: At 9 minutes, pull the basket out and shake (or flip) so every side meets the hot air. Gently separate any sticks that are still clinging together.
Step 5: Finish and Serve: They're done when the edges are golden and a fork slides through easily. Scatter the optional salt substitute, and eat right away — they soften as they cool.
