In a small mixing bowl, combine cream cheese, mayonnaise and horseradish.
Assemble pinwheels by spreading a thin layer of the cream cheese mixture over each tortilla.
Layer roast beef, spinach and shredded cheese. Tightly roll up each tortilla and wrap it with plastic wrap. Refrigerate for at least 2 hours.
To serve, slice each roll into one-inch slices.
Notes
If you are using a creamy horseradish you may need to add a little more to get the same flavor. And adjust the flavor by using more or less horseradish sauce.If you are having trouble getting the tortillas to stick together, you can use a small amount of the cream cheese mixture at the seams or use toothpicks to help hold the rollups together.If you have any leftovers, they will need to be stored in an airtight container in the fridge. They will last for up to three days. The longer these roll ups sit in the fridge the more likely they are to become soggy.