Heat the oil in a frying pan over medium heat and cook the onion until softened and fragrant, about 3-4 minutes. You can also do this step in the slow cooker if it has a saute function.
Meanwhile, in a blender, add coconut milk, garlic, sun-dried tomatoes, Italian seasoning and salt. Blend on high until smooth.
Add the onion and coconut milk mixture to the slow cooker along with the diced tomatoes, white beans, and vegetable broth. Stir to combine. Cook on low for 4-6 hours or on high for 2-3 hours.
When there is half an hour left on the timer, turn the heat to high (if it's not there already) and add in the dry pasta and stir. Stir in the spinach when there are five minutes left on the timer. Season with salt and pepper, to taste. Serve warm sprinkled with some freshly grated parmesan cheese and fresh basil, if desired.
