Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Chop the zucchini, red bell pepper, and red onion into 1-inch chunks, and halve the baby potatoes so they cook evenly.
Slice the chicken breast into 1-inch strips or bite-sized pieces to ensure they roast at the same rate as the vegetables.
Place the chicken, potatoes, and vegetables onto the prepared sheet pan and drizzle with the extra virgin olive oil.
Sprinkle the dried oregano, garlic powder, sea salt, and black pepper over the mixture, tossing everything thoroughly to coat.
Spread the ingredients out into a single layer, ensuring they aren't overcrowded so they roast rather than steam.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken is cooked through and the potatoes are fork-tender.
Remove from the oven and immediately drizzle with fresh lemon juice and garnish with chopped fresh parsley before serving.