Preheat the oven to 400°F. Line a baking sheet with parchment paper.
In a large bowl, combine ground chicken, breadcrumbs, Parmesan cheese, parsley, garlic powder, onion powder, oregano, salt, pepper, and egg. Mix until well combined.
Form the mixture into 1-inch meatballs and place them on the prepared baking sheet.
Drizzle olive oil over the meatballs and bake for 20-25 minutes, or until cooked through and golden brown.
While the meatballs are baking, prepare the quinoa or rice according to package instructions.
In a serving bowl, layer cooked quinoa or rice, cherry tomatoes, cucumber, red onion, and baked meatballs.
Top with crumbled feta cheese and a generous dollop of tzatziki sauce.
Serve warm and enjoy!