Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup and even roasting.
Cut the chicken breast into 1-inch bite-sized pieces and place them in a large mixing bowl.
Prepare the vegetables by chopping the broccoli into bite-sized florets, slicing the zucchini into half-moons, dicing the red bell pepper, and cubing the sweet potato into small 1/2-inch pieces.
In a small jar or bowl, whisk together the extra virgin olive oil, fresh lemon juice, dried oregano, garlic powder, sea salt, and black pepper until the marinade is well emulsified.
Pour the lemon-herb marinade over the chicken and vegetables in the bowl, tossing thoroughly with your hands or a spatula to ensure every piece is evenly coated.
Spread the mixture in a single layer across the prepared sheet pan, ensuring there is enough space between items so they roast and brown rather than steam.
Bake for 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the sweet potatoes are fork-tender and slightly caramelized.
Remove from the oven and let the pan rest for 5 minutes before portioning the meal into airtight containers for your weekly meal prep.