Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Cut the chicken breast and gold potato into uniform 1-inch cubes to ensure even cooking.
Place the chicken cubes, potato cubes, and broccoli florets into a large reusable silicone bag or a large mixing bowl.
Add the olive oil, lemon juice, lemon zest, oregano, garlic powder, sea salt, and black pepper into the bag.
Seal the bag and shake it vigorously for 30 seconds to ensure every piece is thoroughly coated in the fragrant herb marinade.
Spread the contents of the bag onto the prepared sheet pan in a single layer, making sure the pieces are not overcrowded.
Roast for 22-25 minutes, tossing halfway through, until the chicken is cooked through and the potatoes are fork-tender.