Preheat your oven to 400°F and line a baking sheet with parchment paper.
In a small bowl, mix the lemon juice, olive oil, dried herbs, minced garlic, salt, and pepper to create the marinade.
Place the chicken breast in a shallow dish and pour over half of the marinade. Set aside to marinate for 15-20 minutes.
Peel and cube the sweet potato into bite-sized pieces. Toss the cubes with a little salt, pepper, and a drizzle of any remaining olive oil from the marinade if desired.
Cut the broccoli into florets and lightly toss with salt, pepper, and a few drops of olive oil.
Arrange the marinated chicken breast, sweet potato cubes, and broccoli florets on the baking sheet in a single layer.
Roast in the oven for about 20-25 minutes, or until the chicken is cooked through (internal temperature of 165°F) and the vegetables are tender and slightly crispy around the edges.
If desired, broil for an additional 2-3 minutes to achieve extra crispiness on the chicken.
Remove from the oven, slice the chicken if desired, and serve hot with a squeeze of fresh lemon over the top.