For a richer flavor, use sun-dried tomatoes that have been marinated in herbs and garlic. Toast the walnuts lightly in a dry pan or oven to enhance their nutty flavor. Be careful not to burn them! If you don't have milk, you can use water or a neutral-flavored vegetable broth as a substitute. This spread can be stored in an airtight container in the refrigerator for up to 5 days. Consider adding a clove of garlic to the mix for extra pungent flavor.