1. Melt butter and sauté onion and celery until softened in a slow cooker. After adding the garlic, cook for one minute. Add beans, carrots, and ham. Add enough water to cover the beans.
2. Bring the mixture to a boil for around 10 minutes if your slow cooker has that capability. If necessary, add extra water. Cook on low for 6-8 hours or high for 3-4 hours, covered.
3. If you used a ham bone, set it aside to cool before dicing the meat and adding it back to the soup. If you want a thicker soup, crush some of the beans against the pot’s side.
4. Add salt & pepper to taste, garnish with parsley, if desired.

For more ideas on cooking beans in a slow cooker, you can check out this video.