Mix together the kosher salt, garlic powder, onion powder, dried thyme, mustard powder, and black pepper in a small bowl. Drizzle the chicken thighs with the neutral oil and season generously on all sides with the spice blend.
2 to 2½ pounds bone-in, skin on chicken thighs , 1 tablespoon oil, 2½ teaspoons kosher salt, 1 teaspoon garlic powder, 1 teaspoon onion powder, 1 teaspoon dried thyme, 1 teaspoon dried mustard, ½ teaspoon black pepper