Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Trim the woody ends off the Brussels sprouts and slice each one in half lengthwise.
Pat the chicken breast dry with a paper towel and cut it into uniform 1-inch bite-sized cubes.
In a large mixing bowl, combine the chicken cubes and halved Brussels sprouts.
Drizzle with extra virgin olive oil and sprinkle with sea salt, black pepper, garlic powder, onion powder, and smoked paprika.
Toss everything thoroughly until the chicken and vegetables are evenly coated in the oil and spices.
Spread the mixture in a single layer on the prepared baking sheet, ensuring the Brussels sprouts are placed cut-side down to achieve maximum caramelization.
Roast for 20 to 25 minutes, tossing the ingredients halfway through, until the chicken is cooked through and the sprouts are charred and tender.
Remove from the oven and serve immediately while the edges are perfectly crispy.