Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Halve the baby potatoes and mince the garlic clove.
In a small bowl, whisk together the olive oil, lemon juice, minced garlic, dried oregano, sea salt, and black pepper.
Place the chicken breast and halved potatoes on the prepared sheet pan, then drizzle with two-thirds of the lemon-herb dressing, tossing to coat evenly.
Roast in the oven for 15 minutes.
While the chicken and potatoes roast, trim the woody ends off the asparagus spears.
Remove the sheet pan from the oven, add the asparagus, and drizzle with the remaining dressing.
Return the pan to the oven and roast for an additional 10 to 12 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are golden and tender.
Let the chicken rest for 5 minutes before slicing and serving alongside the roasted vegetables.