Rinse the great northern beans under cold water and pick through them to remove any discolored or damaged beans. In a large pot, bring 8 cups of water to a boil with 3/4 teaspoon of salt. Remove from heat, add the cleaned beans, cover, and let them soak for 1 hour. This quick soak method softens the beans while removing some of the compounds that cause digestive discomfort, and it's much faster than overnight soaking.

While the beans are soaking, dice the onion into small pieces, chop the carrots into bite-sized chunks, and dice the celery. Mince the garlic finely. In a small bowl, combine the mustard powder, smoked paprika, and dried thyme—I find mixing the dry spices together first prevents clumping and ensures even distribution throughout the soup. Have the bay leaves and ham hock ready nearby.

After the beans have soaked, do not drain them—they're sitting in flavored water that we want to keep. Bring the pot back to a boil, then add the ham hock, prepared aromatics (onion, carrots, celery, and garlic), the spice mixture from Step 2, and the bay leaves. Stir well to combine and allow the flavors to start melding together. The ham hock will release gelatin and deep, savory flavor as it cooks, which is the foundation of this classic soup.

Once the soup reaches a boil, reduce the heat to low and simmer uncovered for about 1 hour, or until the beans are completely tender and beginning to break down slightly. This extended gentle cooking allows the beans to fully soften, the ham hock to impart all its flavor, and the aromatics to mellow into the broth. Stir occasionally to prevent sticking.

Carefully remove the ham hock from the soup with tongs and set it aside briefly to cool slightly. Once cool enough to handle, pick any meat from the bone and shred or chop it into bite-sized pieces. Discard the bone. Add the shredded ham hock meat back into the soup along with the 2 cups of chopped cooked ham. I prefer adding the ham toward the end so it doesn't get overcooked and lose its texture. Stir in the white pepper and taste the soup, adjusting salt and pepper as needed.

Simmer the soup for an additional 30 minutes to allow the ham to warm through and the flavors to meld together. Ladle into bowls and serve hot. This soup is even better the next day as the flavors deepen, so don't hesitate to make it ahead.