From Beth
I think this is a weight watchers  recipe. I got  this from Anne Manahl.

1 T. Olive oil
1  onion, chopped
1  garlic clove,minced
3  slices Canadian Bacon (diced )(I use  1/3 – 1/2  c.)
1  t. ground cumin
3 14.5 oz  cans black beans
1 T. Tomato  paste
1/2  t. salt
3  T. red  wine vinegar
1 T. dry sherry
shredded cheddar cheese (optional)

In a large nonstick saucepan heat oil. Saute onion and garlic for 5 minutes. Add bacon and cumin, saute until fragrant, about 3 minutes. Stir in the beans and just over 2 cups  water  (the recipe was originally written when beans came in different size  cans, so the proportions are a little different). Cook until thickened, about 15  minutes. With potato masher or side of a wooden spoon, mash some of  the beans. Stir in the tomato paste and salt. Heat to serving. Stir  in the vinegar  and sherry. Served, topped with cheese,  if desired.