Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Dice the sweet potato into 1/2-inch cubes and chop the red bell pepper into bite-sized pieces to ensure even roasting.
Cut the chicken breast into 1-inch chunks so they cook at the same rate as the vegetables.
In a large mixing bowl, whisk together the olive oil, minced garlic, dried rosemary, dried thyme, sea salt, and black pepper.
Add the chicken, sweet potato cubes, broccoli florets, and bell peppers to the bowl, tossing thoroughly to coat everything in the herb oil.
Spread the mixture in a single layer on the prepared sheet pan, making sure the ingredients are not overcrowded.
Roast for 20-25 minutes, or until the chicken is cooked through and the sweet potatoes are fork-tender and lightly browned.
Remove from the oven and serve immediately while the vegetables are crisp-tender and the chicken is juicy.