Preheat oven to 450℉ and line a large baking sheet with parchment paper.
Make the meatballs. In a medium bowl, stir together the breadcrumbs, grated Parmesan cheese, garlic, basil, Italian seasoning, salt, and pepper. Add the ground chicken and egg and stir to combined (I used my hands).
Form 24 equal meatballs (about 1 tbsp each), and place them in a single layer on the prepared baking sheet. Bake in the preheated oven for 15 minutes, or until they reach an internal temperature of 165℉. Set aside.
While the meatballs are baking, make the sauce. Add the oil to a large skillet and heat over medium heat. Add the onion and chopped sun-dried tomatoes and saute for 2-3 minutes. Add the garlic and tomato paste and saute another minute.
Add the chicken broth, half & half, ½ cup freshly shredded Parmesan cheese, Italian seasoning, and salt. Stir to combine and bring to a simmer over medium heat. Once simmering, stir frequently and simmer for 10 minutes.
Add the cooked meatballs to the sauce and toss to combine. Top with the remaining ¼ cup Parmesan cheese and chopped basil. Remove from heat and serve!