Melt Butter Over Medium Heat And Saute Pork And Onions And Fry Until Pork Is Brown On Both Sides. Add 2 Cups Water And Stir. Remove From Stove And Set Aside. In Large Pot, Bring Remaining Water And Stock To A Boil. Add Beans, Tomatoes, Wine And The Pork And Onion Mixture. Reduce Heat To Medium, Cover And Simmer For 2 Hours. Garnish Soup With Cilantro And Serve.