Chop the Green Cabbage (1 head) into about 1-inch chunks. Remove and discard the hard core.
Loosely chop the Sweet Onion (1).
Add green cabbage, sweet onion, Garlic (1 teaspoon), Olive Oil (1 tablespoon), Water (3 tablespoon), Salt (1 tablespoon) and Freshly Ground Black Pepper (1/2 teaspoon) to your slow cooker.
Cook on high until browned and wilted, about 4-5 hours.
Towards the end of cooking the cabbage, cook the Campanelle Pasta (12 ounce) according to package directions. Set aside until the cooking of the cabbage is done.
When the cabbage is done, set your slow cooker to low heat. Add the noodles and Butter (3/4 cup), mixing well.
Cook on low for a final 10-15 minutes, periodically mixing to melt and incorporate the butter. Serve warm!