Heat the oil in a large, deep skillet over high heat. Add the beef, onion, bell pepper, and garlic, and cook (uncovered) until the meat is browned and the vegetables are tender, about 8 minutes, stirring occasionally.
Add the diced tomatoes, tomato paste, water or stock, taco spice blend, salt, black pepper, and black beans, and bring up to a boil. Turn the heat down and simmer (uncovered) 5 minutes, stirring occasionally.
Turn the heat down to low, sprinkle the cheddar shreds on top, and cover the skillet. Cook until the shreds are melted, about 3 minutes (do not stir).
Serve with the parsley or cilantro sprinkled on top.