Start by adding the finely diced onion and carrots into a frying pan with a tbsp of olive oil. Sweat for around 6 minutes until the onions become translucent, then add the garlic to fry for 2 minutes. Season generously with salt and pepper.
Meanwhile, fry the bacon pieces until they start to become crispy and browned.
To the slow cooker, add the fried onion, carrot, garlic and half of the cooked bacon (reserving half for the topping), then add the beans and sun-dried tomatoes. Pour the stock into the slow cooker and stir. Pop the lid on and set the cooking setting to high, set your timer/alarm to 5 hours.
After 4 hours, add the cavolo nero and the rosemary into the pot to infuse for the last hour, no need to use string to tie the rosemary together, you can use some tongs to remove at the end.
When the 5 hours is up, serve the soup with a dollop of creme fraiche, some crispy bacon and a sprinkle of Pecorino. Enjoy!