Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Wash the potato and cut it into small 1/2-inch cubes to ensure they cook at the same rate as the chicken.
Cut the chicken breast into 1-inch bite-sized pieces and place them in a large mixing bowl with the potatoes and broccoli florets.
In a small separate bowl, whisk together the Greek yogurt, olive oil, dried dill, garlic powder, onion powder, sea salt, and black pepper until smooth.
Pour the creamy ranch mixture over the chicken and vegetables, tossing thoroughly to ensure every piece is well-coated.
Spread the mixture in a single layer on the prepared baking sheet, leaving space between pieces for even roasting.
Bake for 25 to 30 minutes, or until the potatoes are fork-tender and the chicken reaches an internal temperature of 165°F.
Remove from the oven and let rest for 2 minutes before serving to allow the juices to redistribute.