Cover the meat with water add salt, bring to boil. Reduce heat, simmer 40 minutes. Allow the pork to cool reserving the broth. Shred pork. Saute chorizo, tomatoes, onions, until the onion is transparent and sausage is done. Add all ingredient s+ 1/2 cup of reserved broth to a pan. Simmer for 10 minutes. It shoud be moist but not liquidy. Serve as tostada filling.