Prepare the Meatballs:In a food processor, blend onion, garlic, basil, and sun-dried tomatoes into a coarse paste. In a large bowl, combine the paste with ground chicken, egg, seasonings, Parmesan, and breadcrumbs. Mix until well combined. Using oiled hands or a scoop, form into small meatballs.
Sear the Meatballs:Heat sun-dried tomato oil in a skillet or use your slow cooker’s sauté setting. Brown meatballs on all sides, about 5 minutes total. They don’t need to be fully cooked at this stage.
Deglaze and Slow Cook:Deglaze the pan with white wine and simmer briefly. Transfer meatballs to the slow cooker. Add chicken broth. Cover and cook on HIGH for 2–3 hours or LOW for 4–5 hours.
Add Sauce Ingredients:Stir in the cream, chopped sun-dried tomatoes, Parmesan, and gnocchi. Cover and cook on HIGH for an additional 20 minutes, until gnocchi are tender and the sauce thickens.
Finish with Spinach:Stir in chopped spinach and cook just until wilted. If desired, add a cornstarch slurry to thicken the sauce. Taste and adjust seasoning as needed.
Serve:Ladle into bowls, sprinkle with more Parmesan, and serve hot!