Preheat your oven to 400°F (200°C).
Halve the baby potatoes and trim the woody ends off the asparagus spears.
In a small bowl, toss the potatoes with 0.5 tbsp of olive oil, half of the garlic powder, and a pinch of salt and pepper.
Spread the potatoes on a parchment-lined baking sheet and roast for 10 minutes.
While potatoes roast, season the chicken breast with the remaining garlic powder, salt, and pepper.
Heat the remaining 0.5 tbsp of olive oil in a large oven-safe skillet over medium-high heat.
Sear the chicken for 3 minutes on each side until a golden crust forms.
Remove the potatoes from the oven and add them to the skillet along with the asparagus.
Drizzle the lemon juice over the chicken and vegetables, then sprinkle with lemon zest and fresh rosemary.
Transfer the skillet to the oven and roast for 12-15 minutes until the chicken is cooked through and the asparagus is tender.