In a large bowl, combine ground chicken, breadcrumbs, grated Parmesan, egg, minced garlic, chopped fresh rosemary, olive oil, salt, and black pepper. Mix gently until just combined. Let the mixture sit while you prepare a baking sheet lined with parchment paper for chilling.

Using your hands, scoop out portions of the mixture and roll them into 1-inch meatballs. Place the formed meatballs onto the parchment-lined baking sheet. Refrigerate for at least 30 minutes.

Preheat your oven to 400°F (200°C). This ensures the meatballs cook evenly.

Bake the meatballs on the sheet for 20-25 minutes or until they reach an internal temperature of 165°F (74°C).

In a large saucepan, heat a tablespoon of olive oil over medium heat. Add the chopped onion and sauté until softened. Stir in minced garlic and cook for an additional minute.

Stir in crushed tomatoes, tomato sauce, dried oregano, dried basil, salt, and pepper. Bring to a simmer for about 5-7 minutes.

Add the orzo and chicken broth to the sauce, stirring to combine. Bring to a boil, then reduce heat to low. Cover and simmer for 10-12 minutes.

Carefully add the baked meatballs to the tomato orzo mixture. Stir gently to combine and simmer on low for another 5 minutes.

Taste and adjust seasoning if necessary. Serve warm, garnished with fresh basil and grated Parmesan.

Allow any leftovers to cool before storing in an airtight container for up to 3 days.