Heat 1 tablespoon oil over low heat in a large heavy-based skillet. Add the chopped onion and cook for 3 minutes. Add the minced garlic and cook for another 2 minutes.
Place the cooked onion and garlic into a large bowl and spread out so it cools quickly. Add the breadcrumbs, sundried tomatoes, salt, Italian seasoning and black pepper to the onion mixture and stir to combine.
Once cool, add the egg, grated Parmesan and the ground chicken. Use your hands to combine. Roll 1½ tablespoon amounts into small meatballs.
Pour the remaining olive oil into the same pan you cooked the onions in and heat over medium heat. Cook the meatballs for 2 to 3 minutes, until browned.
Add the 2 tablespoons oil, chopped onion, minced garlic, wine, sun-dried tomatoes, broth, salt, pepper and Italian herbs to the slow cooker.
Add the meatballs, cover and cook on high for 3 hours.
Add the gnocchi, cream, and sundried tomatoes to the slow cooker and stir to combine. Cover and cook on high for about 20 minutes until the gnocchi is tender.
Stir in the spinach and grated Parmesan and cook for 5 minutes more until the spinach has wilted.
