Step 1

In the bowl of a stand mixer, combine the cream cheese, horseradish, and mustard, creaming together until everything's evenly incorporated.

Step 2

Top each cracker with a generous spoonful of the cream cheese mixture, and use the back of the spoon to gently 'spread' the mixture out onto the cracker. Top the cream cheese spread on the crackers with the shaved roast beef.

Step 3

If using the garnish, sprinkle the prepared crackers with chopped parsley. Serve immediately, so that the crackers stay crisp.