Preheat oven to 400 degrees. Rinse brussels sprouts, cut stems, slice in half, and add brussels to a large mixing bowl. Toss with olive oil, onion powder, garlic powder, salt and pepper. In a large cast iron pan, add brussels sprouts and roast for about 30 minutes, turning halfway through.
In a heated sauté pan, add pancetta, and cook until crispy. Set aside. When the brussels are done roasting, combine crispy pancetta to cast iron pan and gently mix. Drizzle reduced-balsamic or balsamic glaze and serve hot.