Preheat oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Trim the woody ends off the asparagus and slice the red bell pepper into thin strips.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
Place the chicken breast, asparagus, and bell peppers on the prepared baking sheet in a single layer.
Drizzle the olive oil over the chicken and vegetables, then squeeze the juice from the lemon half over everything.
Sprinkle the minced garlic, chopped herbs, sea salt, and black pepper evenly across the ingredients.
Use your hands or tongs to toss the vegetables and coat the chicken thoroughly in the oil and seasonings.
Roast for 20 to 25 minutes, or 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 it stays incredibly moist and flavorful.