These open faced sandwiches are a New Year's Eve tradition in the Czech Republic & Slovak Republic. I only prepare these once a year and that is on New Year's Eve, as was done when I was a growing up and I have always kept it that way. But of course these can be prepared for any sort of occasion. I have added the recipes for some of the more traditional toppings. Feel free to use any other toppings you desire. A few others are, small slices of smoked pink salmon, quality cream cheese or Liptauer spread instead of butter or the mayonnaise and try adding sliced pickled baby beets, which are delicious! Dobrou chut'!