Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Peel the sweet potato and cut it into 1/2-inch cubes, then place them on the prepared baking sheet.
Toss the sweet potato cubes with 0.5 tsp of the olive oil and a pinch of the sea salt and black pepper.
Roast the sweet potatoes for 15 minutes until they begin to soften and slightly brown on the edges.
While the potatoes roast, cut the chicken breast into 1-inch bite-sized pieces and trim the ends off the green beans.
Remove the pan from the oven, slide the potatoes to one side, and add the chicken pieces and green beans to the empty space.
Drizzle the remaining 0.5 tsp of olive oil over the chicken and beans, then season the entire pan with garlic powder, dried oregano, and the remaining salt and pepper.
Return the pan to the oven and bake for 12-15 minutes until the chicken is cooked through and the green beans are vibrant.
Sprinkle the shredded mozzarella cheese over the chicken and sweet potatoes.
Switch the oven to broil for 1-2 minutes until the mozzarella is bubbly and golden, then serve immediately.