Petite beef crostini with Béarnaise aoli

Over the next few days I'm going to post some photos from the events I've worked on over the last month. Unfortunately I only have a few photos since my phone likes to die just as I'm pressing the camera option. Either that or I never charge my phone fully enough, then I make the mistake of calling my aunt on my way to work - she just loooves to talk.  Anyhoo this petite bite is quite simple and has wonderful flavor. You can make most of the components in advance and serve at room temperature, which makes this a great hors d'oeuvre for a cocktail party. By sing a béarnaise aoli (mayonnaise) instead of more traditional sauce this dish is become super simple, and accessible to any level cook. Your guests will absolutely love this delicious dish. 
PREP & ASSEMBLE: 
- Grill your choice of beef with s&p (fillet or flank works well) until medium rare. Let the meat rest and thinly slice. If cooking ahead of time pack up the meat with the released juices. Do not serve straight from the refrigerator! The meat has to come to room temp or slightly warm so the fat isn't hard and waxy.  
- You can make your own mayo or use store bought (about 1 cup). Whisk in 4tbs warm (not hot) melted butter (sweat 2 shallots in the butter first) and a splash of tarragon vinegar then add finely chopped shallots, julienned tarragon, chopped chervil (optional) season with a pinch of s&p. 
- thinly slice baguette drizzle with evoo s&p and lightly toast. 
SERVE: You can serve this app at room temp or slightly warmed. Spread a generous amount of aoli on the toast, then gently drape the meat on top. I would garnish with a tarragon or chervil leaf for a lovely presentation.