Preheat your oven to 400°F (200°C) and line a large rimmed sheet pan with parchment paper for easy cleanup.
Peel and cube the sweet potato into 1/2-inch pieces, and trim and halve the Brussels sprouts.
Cut the chicken breast into uniform 1-inch chunks to ensure they cook at the same rate as the vegetables.
In a small mixing bowl, whisk together the honey, tamari, minced garlic, olive oil, and red pepper flakes until well combined.
Place the chicken, sweet potatoes, and Brussels sprouts on the prepared sheet pan and season with sea salt and black pepper.
Pour the honey-garlic glaze over the ingredients and toss thoroughly with your hands or tongs until everything is evenly coated.
Spread the mixture out into a single layer, ensuring the Brussels sprouts are cut-side down for maximum caramelization.
Roast for 20-25 minutes, tossing halfway through, until the chicken is cooked through and the vegetables are tender with crispy edges.