Hasselback Potatoes

Why This Hasselback Potatoes Works

In the oven, the potatoes slowly dry on the outside while the inside steams. All those thin cuts let the heat move deep into the potato, so the centers become soft and fluffy instead of staying hard. At the same time, the edges of each slice are exposed to the hot air, so they start to brown and crisp up like a bunch of tiny potato chips attached to a baked potato.

As the butter and olive oil warm up, they slide down into the slits. The fat coats the potato slices so they don’t dry out, and the garlic, salt, and pepper spread into all the little gaps instead of just sitting on the surface. Later, when the Parmesan goes on, it melts and sticks to the hot, oily edges, then firms up again into a thin, salty crust. By the time the potatoes come out, the outside is crunchy and cheesy, the inside stays tender, and the herbs cling to the top instead of falling off.

Mistakes To Avoid

Cutting the potatoes all the way through instead of stopping just before the bottom makes the slices fall apart on the tray. The pieces then cook like small wedges instead of a single fanned potato, so the centers can stay firm while the edges dry out and burn.

Slicing the potatoes too thick or too far apart keeps the heat from reaching the center in time. The outside turns brown and crisp, but the inside stays hard and undercooked, even after the full baking time.

Letting the oven run cooler than 425°F causes a different problem: the potatoes slowly dry out before they ever get crisp. The slices stay pale and soft, and the butter mixture just soaks in instead of helping the edges turn golden.

Adding the Parmesan at the start of baking instead of near the end makes the cheese burn on the outer slices. The tops go dark and bitter while the inner parts of the potato are still soft and not fully crisped.