Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Halve the baby potatoes and place them on one side of the pan, tossing with half of the olive oil and a pinch of salt and pepper.
Roast the potatoes for 15 minutes to give them a head start on becoming golden and tender.
While the potatoes roast, whisk together the remaining olive oil, lemon juice, lemon zest, minced garlic, and dried oregano in a small bowl.
Pat the chicken breast dry with a paper towel and season both sides with the remaining salt and pepper.
Remove the pan from the oven and add the chicken, trimmed asparagus, and cherry tomatoes to the empty space.
Drizzle the prepared lemon-herb mixture over the chicken and vegetables, ensuring everything is lightly coated.
Return the pan to the oven and roast for another 15 to 20 minutes, or until the chicken reaches an internal temperature of 165°F and the asparagus is crisp-tender.
Let the chicken rest for 5 minutes before slicing to keep it juicy, then serve immediately with the roasted vegetables.