Place cut potatoes in a large bowl and toss with kosher salt. Let sit while you prepare the seasoning and oil (about 5 minutes) so salt starts to draw out moisture for crisper edges.

Seasoning & oil

In a small bowl combine chili powder, smoked paprika, ground cumin, onion powder, ground black pepper and sugar (if using). Stir to blend evenly.

In a second small bowl or measuring cup combine olive oil and melted or softened butter. Add minced garlic and whisk briefly to combine. Pour the oil mixture over the salted potatoes and toss well so every piece is lightly coated.

Sprinkle the dry seasoning mix over the oiled potatoes and toss until evenly coated. Use your hands or a spatula to ensure the spices adhere to the oil-coated surfaces.

Roast potatoes

Arrange the seasoned potatoes in a single layer on a rimmed baking sheet lined with parchment or a silicone mat. Leave a little space between pieces so they roast instead of steam.

Roast in the preheated oven for 25–35 minutes, turning once halfway through, until potatoes are golden and crisp on the edges and tender when pierced with a fork. Smaller pieces will take closer to 25 minutes; larger pieces up to 35 minutes.

Finish & serve

Remove the potatoes from the oven. Immediately drizzle with fresh lime juice and sprinkle lime zest over the hot potatoes so the citrus aroma is bright and distributed.

Transfer potatoes to a serving bowl or platter. Scatter chopped cilantro and optional crumbled cotija or feta across the top. Taste and finish with flaky sea salt to taste (about 1/2 tsp recommended).

Serve warm as a side or snack. Leftovers keep refrigerated up to 3 days; reheat in a 400°F (200°C) oven for 8–10 minutes to restore crispness.