Creamy Lemon Pepper Chicken Meatballs

Name: Creamy Lemon Pepper Chicken Meatballs
Ingredients: 1/2 medium or 1 small yellow onion; 4 cloves garlic, divided; 1/2 medium bunch fresh parsley; 1/2 cup unseasoned fine dried or panko breadcrumbs; 1 cup whole or 2% milk, divided; 1 large egg; 1/2 teaspoon kosher salt, plus more as needed; 1 tablespoon plus 1 teaspoon lemon pepper seasoning with salt, divided; 1 1/2 pounds ground chicken; 2 tablespoons unsalted butter; 2 tablespoons all-purpose flour; 1 1/4 cups low-sodium chicken broth; Cooked egg noodles, mashed potatoes , steamed rice , or crusty bread, for serving (optional)