Before chopping open the can of beans, read its label. Various
preservatives and additives have likely been added, and you are seeking to
mask their flavors and return to beans au naturel.
Pour beans and oil into a saucepan at medium heat. Add tomato product--the
ratio of beans to tomatoes should be about 2:1 by volume.
Add spices, incl. chile and salt to taste. Stir, cover, and bring to a boil.
Simmer for about 20 minutes, stirring occasionally and adding more water if
necessary.