Hasselback Sweet Potatoes With Thyme, Pecans and Parmesan
A fully savory hasselback sweet potato: fans roasted open at high heat, thyme pushed down into the slits, then toasted pecans and finely grated parmesan added in the last ten minutes so the cheese crisps into lace instead of burning.
Servings 4 servings
Ingredients
For the Potatoes
- 4 medium sweet potatoes 6 to 8 ounces each, scrubbed, skin on
- 3 tablespoons olive oil
- 2 cloves garlic minced
- ½ teaspoon smoked paprika
- 1 teaspoon kosher salt
- ½ teaspoon black pepper
For the Finish
- 1 tablespoon fresh thyme leaves plus a few small sprigs
- ⅓ cup pecans toasted and roughly chopped
- ⅔ cup Parmigiano Reggiano finely grated
Instructions
Cut the Potatoes
- Heat the oven to 400F. Scrub the sweet potatoes and dry them completely, leaving the skins on.
- Trim a thin sliver off one long side of each potato so it sits flat and cannot roll.
- Lay a wooden chopstick or thin skewer tight along each long side of the potato, or set the potato in the bowl of a large wooden spoon. Slice straight down in even cuts a scant ¼ inch apart, letting the blade stop on the sticks so about a half inch of uncut potato holds the slices together at the base. Slow down over the tapered ends.
Roast and Finish
- Stir the garlic, smoked paprika, salt and pepper into the olive oil. Rub it over the potatoes, working it down into the cuts with your fingers, and arrange them in a shallow baking dish with about an inch of space between them.
- Roast for 35 minutes, until the fans have clearly opened and the cut faces look dry and browned at the tips.
- Tuck the thyme leaves and small sprigs down into the slits, then baste the potatoes with the seasoned oil collected in the dish. Return to the oven for 10 minutes.
- Scatter the grated parmesan over the tops, tapping the dish so some falls into the gaps, then add the toasted pecans. Roast 10 to 12 minutes more, until the cheese on the ridges is golden and lacy.
- The potatoes are done when a thin knife slides into the thickest part with no resistance, about 55 minutes total. Rest 5 minutes so the cheese sets, then finish with a little more thyme and black pepper.
Notes
- Cheese and nuts go on late: the last 10 to 12 minutes only. Parmesan turns bitter and pecans go acrid well before a sweet potato is cooked through.
- Toast the pecans separately: 3 minutes in a dry pan before they ever see the oven.
- Grate the parmesan fine: a microplane gives cheese that slides into the slits and crisps on the ridges. Pre-shredded cheese clumps.
- Space in the dish: an inch between potatoes, or they steam each other and the fans stay soft.
- Skin on: it crisps, it holds the uncut base together, and a peeled potato is slippery to slice.
- Storage: 4 days refrigerated. Reheat at 400F for 10 minutes or in an air fryer at 370F for 5 minutes, never the microwave.