Seared Beef Tenderloin Mini Sandwiches with Mustard-Horseradish Sauce

Thinking of making this for a Christmas party im hosting.  What does anyone think of puttong it on crostini instead? 

Made this for our cooking group's first organizational meeting and loved it. I stuck pretty close with the recipe and only cheated and used dried tarragon since I wanted to make the sauce the night before didn't have fresh in the house. We will make the sauce to use on sandwiches because it had a very nice flavor.

Awesome! I followed the recipe except I might have used more capers, had 2-4 on each one. Letting the meat sit for 15 minutes helps it not bleed as much on the bread. You can push the capers into the sauce so the don't roll off.

I made these for a dinner party hors d'oeuvre and everyone loved them. I sliced the French bread straight so I had somewhat smaller appetizers and put just a small amount of tenderloin and everything else on each one. I would definitely make these again. Apparently this recipe was originally from Bon Appetit magazine - the only difference being full-fat sour cream. I found it while searching Epicurious for beef tenderloin appetizers...

This was a huge hit at a party I went to! To cut down the work and time, I used the Boarshead Londonport sliced at the deli and it came out delicious. I'll make it again for sure!

was terrific addition to a holiday open house buffet. It was clearly the favorite dish. Easy to eat, yet a substantial appetizer. Important to let the meat cool so that the juices redistribute and they don't "leak" on your bread and make it soggy. I used arugula instead of watercress - delicious!

Amazing! And the sauce would go great on anything. Have made several times.