Remove chicken thighs from the refrigerator and pat them completely dry with paper towels, especially on the skin side.

In a small bowl, mix together kosher salt, black pepper, garlic powder, smoked paprika, and dried thyme until evenly combined.

Generously rub the seasoning blend over both sides of each chicken thigh, pressing gently to adhere the spices.

Heat a cast iron or oven-safe skillet over medium-high heat for about 2 minutes until very hot.

Add olive oil to the hot skillet, then place chicken thighs skin-side down in a single layer. Sear undisturbed for 4 to 5 minutes until the skin is golden and crisp.

Using tongs, flip each thigh and sear on the flesh side for 2 to 3 minutes until lightly browned.

Transfer the skillet to a preheated 425°F (220°C) oven and roast for 12 to 15 minutes, or until a meat thermometer inserted into the thickest part reads 165°F (74°C).

Remove the skillet from the oven and let the chicken rest for 5 minutes before serving to allow juices to redistribute.