Start by rinsing dried navy beans under cool running water. Soak in water overnight or boil for 2 minutes, then cover and let sit for 1 hour. Drain and set aside.

In a skillet, heat olive oil over medium heat. Sauté diced onion, carrots, and celery for about 5-7 minutes until softened. Stir in minced garlic and cook for an additional minute.

In the crockpot, combine soaked navy beans, sautéed vegetable mixture, ham bone or diced ham, chicken broth or water, dried thyme, bay leaf, and black pepper. Stir gently.

Cover the crockpot and set it to low, cooking for 8 hours or high for about 4 hours, until beans are tender.

During the last 30 minutes, taste soup for seasoning, and adjust with salt. If using a ham bone, remove it, shred any meat, and return it to the soup.

Serve the soup hot, pairing with crusty bread for a complete meal.