Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Peel the sweet potato and cut it into uniform 1-inch cubes to ensure even roasting.
In a small ramekin, whisk together the dried rosemary, thyme, garlic powder, sea salt, and black pepper.
Pat the turkey breast dry with a paper towel, then brush with 0.5 tbsp of olive oil and coat thoroughly with half of the herb seasoning.
Place the sweet potato cubes on one side of the sheet pan, drizzle with 0.25 tbsp of olive oil and the remaining herbs, tossing to coat.
Roast the turkey and sweet potatoes for 15 minutes.
While roasting, trim the woody ends off the asparagus and toss the spears with the remaining 0.25 tbsp of olive oil and lemon juice.
Add the asparagus to the pan and continue roasting for 10-12 minutes, or until the turkey reaches an internal temperature of 165°F and the potatoes are golden.
Let the turkey rest for 5 minutes before slicing to keep it juicy.