Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Wash and halve the baby potatoes, and trim the woody ends off the asparagus spears.
Mince the fresh garlic clove finely.
In a large mixing bowl, whisk together the olive oil, minced garlic, dried oregano, garlic powder, sea salt, and black pepper.
Add the chicken breast and halved potatoes to the bowl, tossing thoroughly to ensure every piece is coated in the herb oil.
Arrange the chicken and potatoes on the prepared baking sheet in a single layer, ensuring they aren't overcrowded.
Roast for 15 minutes, then remove the pan and add the asparagus spears and lemon slices to the remaining space.
Return the pan to the oven for another 10-12 minutes until the chicken reaches an internal temperature of 165°F and the potatoes are golden.
Squeeze the warm roasted lemon slices over the chicken and vegetables just before serving for a bright finish.