Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Place the cubed sweet potatoes on the sheet pan, drizzle with 1 tablespoon of olive oil, and sprinkle with half of the sea salt and black pepper.
Roast the sweet potatoes for 15 minutes to ensure they become tender and slightly caramelized before adding the other ingredients.
While the potatoes roast, whisk together the remaining 1 tablespoon of olive oil, lemon juice, dried oregano, dried thyme, and garlic powder in a small bowl.
Remove the pan from the oven and add the chicken breasts, sliced zucchini, and chopped red bell pepper alongside the potatoes.
Brush the herb and lemon mixture generously over the chicken breasts and toss the vegetables lightly to coat them in the aromatics.
Season the entire pan with the remaining sea salt and black pepper, then return it to the oven for 18-20 minutes.
Bake until the chicken reaches an internal temperature of 165°F and the vegetables are fork-tender.
Remove from the oven, sprinkle the crumbled feta cheese over the top, and let the chicken rest for 5 minutes before slicing and serving.