Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Chop the zucchini, red bell pepper, mushrooms, and onion into uniform, bite-sized pieces.
In a large mixing bowl, combine the ground chicken, chopped vegetables, and extra virgin olive oil.
Sprinkle the garlic powder, dried oregano, sea salt, and black pepper over the mixture.
Using your hands or a large spoon, toss everything together while breaking the ground chicken into small crumbles so it is evenly distributed.
Spread the mixture in a single, even layer across the prepared baking sheet to ensure the chicken browns properly.
Roast in the oven for 20 to 25 minutes, stirring halfway through, until the chicken is fully cooked and the vegetables are tender and slightly caramelized.
Remove from the oven and serve immediately while hot.