Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Wash and dice the red potatoes into 1/2-inch cubes and trim the woody ends off the asparagus.
In a small bowl, whisk together the olive oil, minced garlic, chopped rosemary, chopped thyme, and the juice from the half lemon.
Place the chicken breast, diced potatoes, and asparagus on the sheet pan.
Drizzle the herb oil mixture over the chicken and vegetables, then sprinkle with sea salt and black pepper.
Toss everything well to ensure an even coating, then spread into a single layer so the potatoes can get crispy.
Roast for 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are golden brown and tender.