Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Dice the Yukon Gold potatoes into half-inch cubes to ensure even cooking.
In a small bowl, whisk together the olive oil, lemon juice, oregano, garlic powder, sea salt, and black pepper.
Toss the diced potatoes with half of the herb-oil mixture and spread them in a single layer on the baking sheet.
Roast the potatoes for 15 minutes before adding the other components.
While potatoes roast, brush the remaining herb-oil mixture onto the chicken breast and toss the broccoli florets in any remaining liquid.
Remove the sheet from the oven, move the potatoes to one side, and place the chicken and broccoli on the other side.
Return the sheet to the oven and roast for an additional 18 to 22 minutes, or until the chicken reaches an internal temperature of 165°F.
Garnish with freshly chopped parsley and an extra squeeze of lemon if desired before serving.