Absolutely! You can definitely use your leftover corned beef from St. Patrick’s Day for this instant pot corned beef and cabbage soup. Dice up the corned beef leftovers or shred then and toss them right into the stock! And, it is such a perfect winter dinner! So if you don’t know what to make with leftover corned beef brisket, you’ve found yourself a winning dinner recipe. Have yourself a second St. Paddy's Day feast!