Step 1: Prepare the Potatoes : Preheat the oven to 425°F (220°C). Line a large baking sheet with parchment paper. Wash and scrub the potatoes well (no need to peel). Cut each potato lengthwise into halves, then quarters, and then eighths to form wedges. Soak the wedges in cold water for 20–30 minutes to remove excess starch (this helps them crisp better).
Step 2: Season the Wedges : Drain and pat the potato wedges completely dry using a clean towel. In a large bowl, toss wedges with olive oil, cornstarch, and all seasonings—garlic powder, paprika, onion powder, thyme, salt, and pepper. Coat them evenly.
Step 3: Bake the Wedges : Spread wedges in a single layer on the baking sheet, ensuring they don’t overlap. Bake for 20 minutes, then flip each wedge. Bake another 20–25 minutes until golden brown and crisp on the edges. Sprinkle with fresh parsley.
Step 4: Make the Sour Cream Dip : In a bowl, mix sour cream, mayonnaise, lemon juice, garlic, and chives. Add salt and pepper to taste. Chill for 10–15 minutes before serving.