Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Dice the Yukon gold potato into 1/2-inch cubes and place them in a bowl, tossing with 0.5 tbsp of olive oil, half the sea salt, and half the black pepper.
Spread the potatoes in a single layer on the prepared baking sheet and roast for 15 minutes until they begin to soften.
While potatoes roast, whisk together the remaining 0.5 tbsp olive oil, lemon juice, dried oregano, garlic powder, and chopped fresh rosemary in a small bowl.
Place the chicken breast on the baking sheet next to the potatoes and brush the lemon-herb mixture over both sides of the chicken.
Add the asparagus spears to the sheet pan, drizzling any remaining herb mixture over them and seasoning with the remaining salt and pepper.
Return the pan to the oven and roast for an additional 15 to 20 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are golden and crispy.
Let the chicken rest for 5 minutes before slicing to ensure it remains tender and juicy.