Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Peel the carrots and slice them into half-inch rounds, then slice the red onion into thick wedges.
Cut the chicken breast into uniform 1-inch cubes to ensure even roasting and juicy results.
In a large mixing bowl, whisk together the avocado oil, turmeric, sea salt, black pepper, and garlic powder until well combined.
Add the chicken, carrots, and onions to the bowl and toss thoroughly until every piece is vibrantly coated in the golden spice oil.
Spread the mixture in a single layer on the prepared baking sheet, making sure not to crowd the ingredients so they roast rather than steam.
Bake for 20 to 25 minutes, tossing halfway through, until the chicken is cooked through and the carrots are tender-crisp with caramelized edges.
Remove from the oven, drizzle with fresh lemon juice to brighten the flavors, and garnish with chopped fresh parsley before serving.