Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper to prevent sticking without using oil.
Peel and cube the sweet potatoes into 1/2-inch pieces and place them in a bowl.
Toss the sweet potatoes with 1 tablespoon of lemon juice, the dried rosemary, and a pinch of sea salt.
Spread the sweet potatoes in a single layer on one side of the prepared baking sheet and roast for 15 minutes.
While the potatoes roast, season the chicken breast evenly with garlic powder, dried thyme, lemon zest, sea salt, and black pepper.
Remove the baking sheet from the oven, move the potatoes to one side, and place the chicken breast and trimmed asparagus on the other side.
Drizzle the chicken and asparagus with the remaining lemon juice and the chicken broth to keep the meat moist during roasting.
Return the sheet to the oven and bake for an additional 15 to 20 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are tender.
Let the chicken rest for 5 minutes before slicing and serving alongside the roasted vegetables.