Position a rack in the upper-middle of the oven and preheat to 425°F (220°C). Allow the oven to fully come to temperature so the potatoes crisp quickly.

Prepare potatoes

Wash the potatoes well. If using larger potatoes, cut into 1 to 1½-inch chunks so pieces are roughly uniform. Leave skins on for texture and flavor.

Parboil

Place the potato chunks in a large pot and cover with cold water (about 2 qt). Add 1 tablespoon kosher salt. Bring to a gentle boil and cook for 8–10 minutes, until the edges are just tender but the centers are still firm when pierced with a knife. You want them slightly undercooked so they hold shape during roasting.

Drain and rough up

Drain the potatoes in a colander and let steam-dry for 1–2 minutes. To create rough surfaces that crisp well, shake the colander back and forth a few times or toss gently in the pot with the lid on to abrade the edges.

Toss with oil and seasonings

In a large bowl, combine 4 tbs extra-virgin olive oil, 2 tsp chopped rosemary, 4 minced garlic cloves, 1.5 tsp kosher salt, 1 tsp freshly ground black pepper, and 0.5 tsp smoked paprika if using. Add the warm, slightly roughened potato pieces and toss thoroughly so each piece is lightly coated with oil and seasonings.

Arrange on baking sheet

Spread the potatoes in a single layer on a rimmed baking sheet (line with parchment if desired). Arrange cut sides down when possible and avoid crowding — use two sheets if necessary to keep space between pieces for maximum crisping.

Roast

Roast in the preheated 425°F oven for 25–35 minutes, turning once or twice with a spatula so all sides brown evenly. Roast until deep golden brown and crisp on the outside and tender inside. Total time depends on potato size and oven; check at 25 minutes.

Finish

Remove from oven and immediately toss with the lemon zest (1 tsp) if using and the chopped parsley (2 tbs) for brightness and color. Taste and adjust seasoning with a pinch more salt or pepper if needed.

Serve

Serve hot as a side dish. These roast potatoes pair well with roasted meats, grilled fish, or as part of a brunch spread.