Preheat your oven to 425°F. Lightly spray a 9x13-inch baking dish with cooking spray.
Place the cubed chicken directly into the prepared baking dish.
In a small bowl, mix the dry mustard, chives, parsley, garlic powder, paprika, thyme, salt, black pepper, cayenne pepper, and red pepper flakes until well combined. Make sure to mix thoroughly for an even flavor.
Sprinkle the seasoning mixture over the chicken. Drizzle with olive oil and gently toss to coat the chicken evenly.
Top the chicken with cubed butter, spreading it across the chicken. This will melt and create a rich sauce during baking.
Bake for 10 minutes, then stir the chicken. Return it to the oven and bake for another 8-10 minutes, or until the chicken reaches an internal temperature of 165°F and the edges are lightly browned. Use a meat thermometer to ensure perfect doneness.
Once cooked, remove from the oven. Garnish with freshly chopped parsley and serve immediately. A squeeze of fresh lemon juice before serving adds a refreshing touch!
Notes
For added flavor, you can squeeze some fresh lemon juice over the chicken before serving.