Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Peel and dice the sweet potato into 1/2-inch cubes and place them on one side of the baking sheet.
Drizzle the sweet potatoes with half of the olive oil and a pinch of salt and pepper, tossing to coat evenly.
Place the chicken breast on the other side of the sheet, rubbing it with the remaining olive oil, minced garlic, oregano, thyme, salt, and pepper.
Arrange the lemon slices on top of the chicken and sweet potatoes to infuse them with bright citrus flavor.
Roast in the oven for 15 minutes, then remove the pan and add the trimmed asparagus to the remaining space.
Return to the oven for another 10 to 12 minutes until the chicken reaches an internal temperature of 165°F and the vegetables are tender.
Let the chicken rest for 5 minutes before slicing to ensure the juices remain locked in for a moist result.