Look over the beans and remove any rocks or broken beans. Rinse the beans and put in a large pot. Add water, about 8 cups or enough to cover by at least an inch. Bring to a boil on stove. Add onions, garlic, bay leaf and ham hock. Return to a boil. Reduce heat, cover and simmer for 2 to 3 hours, stirring occasionally. Makw sure you don't run out of water and that the beans don't scorch. Add more water if necessary.
After beans have softened (about 2 hours), add salt and pepper to taste.
Continue cooking until beans are done. Make sure the soup is not too thick or too thin. (I usually get it too thick but you can always add water to thin it out.). Remove bay leaf and serve.