Roast Beef with Horseradish Cream

16 sandwiches

1/4 cup mayo
1 tsp horseradish
1/2 tsp chopped fresh parsley
1/2 tsp dijon mustard
8 slices thin white sandwich bread crust removed
1/3 lb thinly sliced deli roast beef.

In bowl, combine mayo, horseradish, parsley and mustard.

Spread mixture evenly over bread. 

Top four slices w/ roast beef.

Place remaining bread over beef and cut into quarters.