Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Peel the sweet potato and dice it into small 1/2-inch cubes to ensure even cooking with the other ingredients.
Cut the chicken breast into bite-sized pieces and slice the red bell pepper into thin strips.
Place the chicken, sweet potato cubes, broccoli florets, and bell pepper strips in a single layer on the prepared sheet pan.
In a small glass jar or bowl, whisk together the olive oil, lemon juice, minced garlic, dried oregano, sea salt, and black pepper.
Drizzle the lemon-herb dressing over the chicken and vegetables, tossing everything thoroughly with your hands or tongs to coat.
Roast in the oven for 20 to 25 minutes, or until the chicken is cooked through and the sweet potatoes are fork-tender.
Let the meal cool slightly before transferring to airtight containers to store in the refrigerator for up to five days.