Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Peel the sweet potato and cut it into 1/2-inch cubes, and slice the zucchini into thick half-moons.
Cut the fresh chicken breast into uniform 1-inch pieces, ensuring the meat is fresh or flash-frozen to keep histamine levels low.
Place the chicken, sweet potato cubes, and zucchini slices onto the prepared baking sheet.
Drizzle the olive oil over the ingredients and sprinkle evenly with sea salt and garlic powder.
Toss everything thoroughly with your hands or tongs until well-coated, then spread into a single layer so nothing is crowded.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken is cooked through and the sweet potatoes are golden and tender.
Remove from the oven and immediately garnish with freshly chopped parsley before serving.