Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Dice the red potato into small 1/2-inch cubes and chop the zucchini, bell pepper, and red onion into uniform bite-sized pieces.
Place the chicken breast on one side of the baking sheet and arrange the potatoes, zucchini, peppers, and onions on the other side.
In a small glass jar or bowl, whisk together the extra virgin olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Drizzle the herb dressing over the chicken and vegetables, tossing the vegetables with tongs to ensure they are well-coated.
Roast in the center of the oven for 15 minutes, then remove briefly to add the cherry tomatoes to the vegetable side.
Return to the oven and roast for an additional 10-12 minutes until the chicken reaches an internal temperature of 165°F and the potatoes are fork-tender.
Let the chicken rest for 5 minutes before slicing it against the grain, then garnish the entire dish with fresh chopped parsley.