Preheat your oven to 400°F. Line a baking sheet with parchment paper.
In a small bowl, combine olive oil, lemon juice, minced garlic, mixed dried herbs, salt, and pepper.
Place the chicken breast on one side of the baking sheet and brush with the prepared herb mixture.
Dice the sweet potato into 1/2-inch cubes and toss with a pinch of salt, pepper, and a drizzle of olive oil. Arrange on another section of the baking sheet.
Place the green beans on a separate part of the baking sheet, drizzle with a little olive oil, and season with salt and pepper.
Roast everything in the preheated oven. Bake the chicken for 20-25 minutes until its internal temperature reaches 165°F, the sweet potatoes for 25-30 minutes until tender and slightly caramelized, and the green beans for about 15-20 minutes until crisp-tender.
Optionally, if you prefer extra crispiness on the green beans, broil them for an additional 2-3 minutes, watching carefully.
Remove from the oven, let the chicken rest for a few minutes, then slice and serve alongside the roasted sweet potatoes and green beans.