What causes the rainbow sheen on ham? That metallic-looking rainbow that often appears on sliced deli meat is known as iridescence, a phenomenon in which changing your position to the object causes ...
Heat half of the oil in a frying pan and fry the beef pieces for 4–5 minutes, or until browned all over. (You may need to brown the meat in batches.) Tip the browned meat into the slow cooker.