Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Slice the baby potatoes into halves and trim the tough, woody ends off the asparagus spears.
In a small bowl, combine the finely chopped rosemary, thyme, garlic powder, sea salt, and black pepper.
Place the chicken breast and halved potatoes on the baking sheet, drizzle with olive oil, and rub with the herb mixture.
Roast the chicken and potatoes for 15 minutes in the center of the oven.
Remove the pan, add the asparagus to the empty spaces, and squeeze the juice of half a lemon over the entire tray.
Return to the oven and roast for an additional 10 to 12 minutes until the chicken reaches an internal temperature of 165°F.
Let the chicken rest for 5 minutes before slicing to ensure it stays juicy, then serve with the roasted vegetables.