Inspect the dried beans carefully, removing any debris, stones, or broken beans. Rinse the beans thoroughly under cool running water using a colander. (Note: Rinsing is essential even if not soaking.)

Optional Sauté: 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. Layer the prepared aromatic vegetables (sautéed or raw) over the beans.

Nestle the large smoked ham bone into the center of the beans and vegetables. Pour in the 6 cups of broth and the 2 cups of water. Ensure all ingredients are submerged; if not, add a little more water until everything is covered by liquid.

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

Cover the slow cooker tightly. 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 beans are tender, carefully remove the ham bone using tongs and place it on a cutting board to cool slightly. Discard the bay leaves.

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

Thicken (optional): If a thicker consistency is desired, smash about 1 cup of the cooked beans against the side of the pot with a spoon, or briefly use an immersion blender to blend a portion of the soup. Stir well to incorporate.

Taste the soup and adjust for salt, if necessary. Stir in the 1 tablespoon of apple cider vinegar or lemon juice to brighten the flavor. Serve hot.