For an extra layer of flavor, consider adding a dash of hot sauce or a sprinkle of red pepper flakes to the chopped mixture. If you don’t have fresh dill on hand, dried dill can be substituted. Use 1 teaspoon of dried dill for every 1 tablespoon of fresh dill. To make ahead, prepare the chopped mixture and store it in an airtight container in the refrigerator for up to 24 hours. Assemble the bagels just before serving to prevent them from becoming soggy.