Quick and Easy – Flank Steak Crostini w/ Horseradish Aioli

Flank Steak CrostiniSeems like Oscar weekend totally snuck up on me this year. Thankfully, I have a mental list of super-fast, super-easy finger foods that I can easily whip up with minimal notice.

As a matter of fact, most of the finger foods and canapes I make are super-fast and super-easy. Basically, if it’s not something that I can prepare well in advance or quickly assemble at the last minute, I’m not interested… I want to spend my time enjoying my party, not futzing with canapes in the kitchen.

However, I absolutely refuse to sacrifice taste for the sake of convenience. It takes almost no time to make miniature weiners in a ketchup and grape jelly sauce, but it’s still a waste of time because miniature weiners are gross. Most appetizers may be just a bite or two, but that means those two bites have to make one hell of a good impression.

That’s what makes these little open-faced steak sandwiches so fabulous.

Flank Steak CrostiniIf these little toasts with medium-rare flank steak, peppery arugula and zippy horseradish aioli were a building, they’d be right on the intersection of Easy and Delicious. Once the aioli is prepared and the steak is broiled, the rest of the prep is dead simple… which is good, because they’ll probably be flying off the plate almost as quickly as you can make them.

Depending on how many slices you can get out of your baguette, you’ll likely end up with some leftover flank steak. If you do, consider it an excuse to make a Black and Blue Flank Steak Salad to reward yourself for a job well done. Or just make some steak sandwiches with the leftover aioli, as there will likely be some of that as well.

Now if only I could find something to wear that’s just as easy and elegant… anyone have suggestions for an outfit that combines the comfort of yoga pants with the glamour of an evening gown? Yeah, me neither.

Note: This aioli is made in the traditional manner, which uses raw eggs, and may not be suitable for everyone (particularly pregnant women, young children or people who are squicked out by raw eggs). If you prefer to play it safe, you can get a reasonable fascimile by adding crushed garlic and prepared horseradish to commercial mayonnaise.


Flank Steak Crostini with Horseradish Aioli

Flank Steak:
2 lb flank steak
2 tbsp Montreal steak spice
Horseradish Aioli:
3 cloves garlic
1/2 tsp salt
1 egg yolk
1 cup olive oil
2 tbsp prepared horseradish
Sourdough baguette, cut into 1/2″ slices on the diagonal
Baby arugula

Preheat the broiler.
Pat the flank steak dry using paper towel. Sprinkle both sides with Montreal steak spice, gently pressing in to make a crust. Transfer to a broiler pan and place under the preheated broiler to cook for 4-5 minutes per side, until cooked to medium-rare or a meat thermometer registers an internal temperature of 165F. Tent with aluminum foil and set aside to rest for 5 minutes, or until ready to serve.
Meanwhile, prepare the aoili. Using a large heavy knife, finely mince the garlic. Sprinkle with salt, then use the flat of the knife to mash the salt and garlic together into a paste. (You can also do this step using a mortar and pestle, if you have one)
Scrape the garlic paste into a small bowl. Add egg yolk, and whisk until smooth. Begin pouring in the olive oil in a thin, steady stream as you whisk briskly, continuing until the oil is completely incorporated and the aoili is thick and smooth. (If the aioli starts to separate at any point during this process, stop adding oil immediately. Whisk the aoili briskly until it comes together again, then continue on as usual)
Stir in horseradish. Taste and adjust seasoning with more salt if necessary. Cover tightly with plastic wrap and refrigerate until ready to use.
To assemble, arrange the baguette slices on a serving platter. Spread each one with a small dollop of horseradish aioli, then top with a few baby arugula leaves.
Cut flank steak into thin slices across the grain. Lay a slice on top of each crostini. Serve immediately.

Note: Steak can also be prepared on the grill in warmer weather. Simply cook the steak on a preheated gas or charcoal grill for 4-5 minutes per side for medium rare, then proceed as usual.


  1. Lavender Blue Wines says

    Love this idea, like a grown up version of a cheesesteak. These look decadent, yet simple to put together. You won me over with the horseradish aioli.

  2. Lo says

    Totally agreed when it comes to short-cutting flavor in appetizers. These look like wonderful bite-sized indulgences… perfect since all the little details (including my favorite — horseradish) in place.

  3. Lemons and Anchovies says

    I can't imagine these crostini not being gobbled up quickly at any party–they're luxe, elegant and delicious! Now why haven't I thought about making these before?

  4. Lawyer Loves Lunch says

    These crostini leave things like pizza bites in the dust. No wonder your guests were eating them as fast as you could make them! :)

  5. Food Frenzy says

    These are fabulous party snacks with a little more bite to them. Love it. Congrats on the Top 9.

    We invite you to share this post and some of your favorite food posts on Food Frenzy.
    Please check out our community at http://blogstew.net/foodfrenzy

  6. Hester aka The Chef Doc says

    OMG, I love this crostini! The flavor combination and textural differences is just right up my alley :-) Thank you so much for sharing this with us! I didn't end up watching any of the Oscars; I hope you had a great time.

  7. kita says

    These look great and no one needs to know how quick they are. I do get tired of always being in the kitchen when companies over. I have got to start thinking of things that can be prepared quickly or ahead of time without lack of flavor or presentation. Ill make sure these go at the top of that list. :)

  8. Isabelle says

    Thanks for the comments, everyone!

    Alaska: Love the idea of brushing the bread with a little olive oil and toasting it. It's a little extra work, but I'm sure it's worth it. (In my case, my baguette was pretty substantial and the crostini were flying off the plate almost as fast as I could make them, so sogginess wasn't a major concern… but I could see it being a problem in other circumstances)

    Ruby: I'm a lazy bum, so I generally just skip the marinade and use a flavourful seasoning instead (like Montreal steak spice). I find that as long as the flank isn't cooked past medium-rare, it's still quite tender.
    You can definitely marinate it beforehand, though, if you're thusly inclined… I particularly like the marinated flank recipe in Bittman's How To Cook Everything.

  9. Ruby says

    Fabulous! The intersection of Easy and Delicious is the heart of my 'hood. One question – do you marinate the steak before grilling it? If so, what kind of marinade do you recommend? OK that was two questions. But they're related. ;-)

  10. Alaska Food and Wine says

    Very nice for Oscar night finger food. I might try this with the baguette slices brushed with olive oil and toasted in a hot oven, so they would stand up to the aioli without getting too soft. Delish!

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