The Night Before: Place the dried beans in a large bowl and cover with three inches of water. Soak the dried beans overnight (up to 24 hours) to soften. Drain when ready to use.
Place a large 6 quart pot over medium heat. Add the oil, ham bone, onions, and garlic. Sauté for 3-5 minutes to soften the onions.
Then add in the drained beans, thyme, ground cumin, crushed red pepper, 10 cups of water, and any remaining ham scraps. (Do not salt the soup until the end, because ham bones can be very salty.)
Bring the soup to a boil. Lower the heat and simmer for 60-90 minutes, covered, until the beans are very soft. Uncover and stir occasionally, then place the lid back on top.
Use a fork to pull any remaining ham off the bone and stir it into the soup. Discard the bone. Add 1-2 cups additional water if the soup is too thick. Taste, then salt and pepper as needed.
Sometimes Nana (and I) add 2-3 chopped carrots, and 2-3 chopped celery stalks to the soup for additional veggie goodness. They are not necessary, but do add a bit of extra color! If using, add the carrots and celery when you add the onions.