For an even richer flavor, consider adding a splash of red wine vinegar or a tablespoon of tomato paste to the stew during the simmering process. Feel free to customize the vegetables in this stew to your liking. Mushrooms, parsnips, or sweet potatoes would all be delicious additions. If you prefer a thicker stew, you can add an extra teaspoon of cornstarch to the slurry. This stew tastes even better the next day, as the flavors have more time to develop. Store leftovers in an airtight container in the refrigerator for up to 3 days.