Preheat your oven to 425°F (220°C). Position the oven rack in the center. Line an extra-large rimmed baking sheet with aluminum foil or parchment paper for easy cleanup.

Pat the chicken thighs thoroughly dry on both sides with paper towels. Achieving ultra-crispy crackling skin requires removing surface moisture completely.

In a small bowl, whisk together 1 tablespoon olive oil, garlic powder, smoked paprika, 1 teaspoon sea salt, and black pepper. Rub this spice blend all over the chicken thighs, ensuring both the top skin and undersides are evenly coated.

In a separate bowl, toss the halved baby potatoes with the remaining 1 tablespoon olive oil, a pinch of sea salt, and half of the chopped rosemary and thyme.

Arrange the seasoned chicken thighs skin-side up on the baking sheet, spacing them evenly apart. Scatter the halved baby potatoes around the chicken in a single layer.

Roast at 425°F (220°C) for 25 minutes. The chicken skin will begin to turn golden and render its savory juices over the potatoes.

While the chicken roasts, stir together the melted butter, minced garlic, lemon juice, and remaining chopped rosemary and thyme in a small dish.

Carefully pull the sheet pan from the oven. Scatter the trimmed green beans and lemon wedges around the chicken and potatoes. Brush the garlic herb butter generously over the chicken thighs and drizzle any remaining butter over the vegetables.

Return the sheet pan to the oven and roast for an additional 12 to 15 minutes, until the chicken thighs reach an internal temperature of 175°F (80°C) on a digital meat thermometer and the skin is shatteringly crisp and blistered.

Remove from the oven and spoon the flavorful pan drippings over the chicken and vegetables. Garnish with fresh rosemary sprigs and serve hot straight from the sheet pan.