Turn leftover saint patricks day corned beef and cabbage into a hearty, homey one-pot soup. Earthy caraway seeds, fresh dill, and pungent malt vinegar give this quick-cooking soup complex flavor. Serve with irish soda bread for a homey and comforting supper. To make this soup without leftovers, use store-bought corned beef (choose a piece about 1 inch thick) and pre-boil the cabbage, potatoes, and carrots until tender, 10 to 15 minutes.