Trim any excess fat from the 5 boneless skinless chicken thighs and pat them dry with paper towels.
In a small bowl combine 1/2 teaspoon Italian seasoning, 1/2 teaspoon dried parsley, 1/2 teaspoon sweet paprika, 1/2 teaspoon garlic powder, 1/2 teaspoon onion powder, 1/4 teaspoon black pepper, and 1/2 teaspoon salt.
Sprinkle the spice mixture evenly over both sides of the chicken thighs and rub it into the meat.
Heat 1 tablespoon olive oil in a large skillet over medium heat until hot, then add 1 tablespoon unsalted butter and let it melt.
Add the chicken thighs to the skillet in a single layer without crowding; cook in batches if needed (3 to 4 at a time).
Cook the thighs 5 minutes on the first side until golden brown, then flip and cook 5 to 7 minutes on the other side until golden and cooked through.
Check doneness with a meat thermometer; the thickest part should read at least 165°F (74°C).
Remove the thighs from the pan and let them rest on a plate a few minutes so the juices redistribute before serving.