Traditional refried beans were leftover beans that were mashed and cooked again -- hence refried. Smoked ham hock is available at most grocery store meat counters and butcher shops. Once cooked, it can be used to add flavor to soups and stocks.
This recipe starts with dried beans. If you're pressed for time, you can quick-soak the beans instead of letting them stand overnight. Cover the beans with water by three inches in a large pot, and bring to a boil. Remove from heat, cover, and let the beans stand for one hour before draining them, and proceed with step 1.