Inspect the dried beans carefully, removing any debris, stones, or broken beans. Rinse the beans thoroughly under cool running water using a colander. (Rinsing is essential; soaking is not required for slow cooker cooking.)

OPTIONAL: If maximizing flavor, heat the tablespoon of olive oil in a large skillet over medium heat. Add the chopped onion, carrots, and celery. Sauté for about 5 to 7 minutes until the vegetables begin to soften. Stir in the minced garlic during the last minute of cooking until fragrant.

Place the cleaned and rinsed dried beans directly into the basin of a large 6-quart or 7-quart slow cooker. Add the prepared aromatic vegetables (sautéed or raw chopped vegetables) over the beans.

Nestle the large smoked ham bone into the center of the beans and vegetables. Pour in the 6 cups of chicken or vegetable broth and the 2 cups of water. Ensure all ingredients are submerged.

Add the seasonings: the two bay leaves, dried thyme, dried parsley, and black pepper. Do not add additional salt at this stage, as the ham bone is salty.

Cover the slow cooker tightly with the lid. Cook the soup on the LOW setting for 8 to 10 hours, or on the HIGH setting for 4 to 5 hours, or until the beans are completely tender and soft.

Once the cooking time is complete, carefully remove the ham bone from the slow cooker using tongs and place it on a cutting board. Discard the bay leaves.

Pick any remaining meat from the bone, shred it or chop it into bite-sized pieces, and return the cooked ham meat to the slow cooker. Discard the remaining bone and any excess fat or gristle.

Check the consistency. If you prefer a thicker soup, mash about 1 cup of the cooked beans against the side of the pot, or briefly use an immersion blender to blend a small portion. Stir well.

Taste the soup and add salt, if necessary. Stir in the 1 tablespoon of apple cider vinegar or lemon juice to balance and brighten the slow-cooked flavors. Serve hot.