In a small bowl, combine the butter, horseradish, parsley, and salt. Cut each baguette in half lengthwise. Spread the butter on both sides of each baguette. Arrange the beef on the bottom half of the baguette. Sandwich with the top half of the baguette. Use a serrated knife to slice each baguette into 12 portions.
These sandwiches are the perfect appetizer for any party. Everyone loved them and the recipe is quick and easy. I've made them several times and I am making them again for a Superbowl party. I do cut them thinner than the recipe calls for.