Preheat your oven to 400°F.
In a bowl, combine the ground turkey, egg white, whole wheat breadcrumbs, fresh parsley, dried oregano, garlic powder, salt, and pepper. Mix gently until all ingredients are well incorporated to form the meatball mixture.
Shape the mixture into meatballs, about the size of a golf ball.
Place the meatballs on a lightly greased baking sheet.
Prepare the vegetables: slice the zucchini, red bell pepper, and red onion into bite-sized pieces and halve the cherry tomatoes.
Toss the vegetables in a bowl with olive oil, salt, and pepper until evenly coated.
Arrange the vegetables around the meatballs on the baking sheet.
Roast in the preheated oven for 20-25 minutes, turning the meatballs halfway through, until the turkey is cooked through and the vegetables are tender.
Remove from the oven and serve warm.