Preheat your oven to 400°F (200°C).
Dice the Yukon gold potato into half-inch cubes and trim the woody ends off the asparagus.
In a small bowl, mince the garlic and whisk together with the dried rosemary, dried thyme, sea salt, black pepper, and half of the olive oil.
Rub the herb and oil mixture evenly over both sides of the chicken breast.
Heat the remaining olive oil in a large oven-safe cast-iron skillet over medium-high heat.
Place the chicken in the skillet and sear for 3-4 minutes until a golden-brown crust forms, then flip.
Scatter the diced potatoes into the skillet around the chicken and transfer the entire pan to the oven.
Roast for 10 minutes, then briefly remove the pan to toss in the asparagus and drizzle everything with lemon juice.
Return to the oven for another 8-10 minutes until the chicken reaches an internal temperature of 165°F and the potatoes are fork-tender.
Let the chicken rest for 5 minutes before slicing and serving with the roasted vegetables.