Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Wash and halve the baby yellow potatoes, then place them on the prepared sheet pan.
Cut the chicken breast into even 1-inch bite-sized pieces and add them to the pan with the potatoes.
In a small bowl, whisk together the olive oil, lemon juice, lemon zest, dried oregano, garlic powder, sea salt, and black pepper.
Drizzle half of the lemon-herb mixture over the chicken and potatoes, tossing well to coat every piece evenly.
Spread the chicken and potatoes in a single layer and roast in the oven for 15 minutes.
While the chicken roasts, toss the broccoli florets in the remaining lemon-herb mixture in a separate bowl.
Remove the pan from the oven, add the broccoli florets, and toss everything together before spreading it back out.
Roast for an additional 10 to 12 minutes until the chicken is cooked through and the potatoes are golden and crispy.
Serve immediately while hot, garnishing with extra fresh herbs or a squeeze of fresh lemon if desired.