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I created these Steak Crostini for my sister's engagement party and they've been my signature appetizer ever since. Every bite brings together buttery toasted baguette perfectly seasoned steak and sweet onions that practically melt in your mouth. The horseradish sauce adds just the right kick and that drizzle of balsamic glaze turns them into pure magic. They look so fancy but trust me they're easier than you think.
Why These Are Always a Hit
Whenever I serve these crostini people gather around the platter like bees to honey. The combination of textures just works crispy bread tender steak and those silky caramelized onions create the perfect bite. I love watching guests' eyes light up when they taste that hint of horseradish. These have become my go to for everything from casual wine nights to holiday gatherings.
Your Shopping List
- Steaks: I splurge on filet mignon when I can but any good steak works beautifully.
- Olive Oil: Use your favorite for both cooking and drizzling.
- Steak Seasoning: My secret weapon for perfect flavor.
- Baguette: Day old is actually perfect for this stiffer slices hold up better.
- Butter: The real deal no substitutes here.
- Garlic: Fresh cloves make all the difference.
- Sour Cream: Full fat creates the dreamiest sauce.
- Horseradish: Start small you can always add more.
- Dijon Mustard: Adds that perfect tangy note.
- Champagne Vinegar: My favorite but white wine vinegar works too.
- Worcestershire Sauce: Just a splash for depth.
- Onion: Sweet yellow ones make the best caramelized onions.
- Sugar: My trick for perfect caramelization.
- Salt and Pepper: Keep them handy you'll use them throughout.
- Balsamic Glaze: That final touch of sweet perfection.
- Chives: Fresh from my garden when possible.
Let's Make Some Magic
- First The Star of the Show
- I season those beautiful steaks generously and let them come to room temperature. A hot grill and 4-5 minutes per side gives me perfect medium rare. The hardest part is waiting 10 minutes while they rest.
- That Amazing Sauce
- While the meat rests I whip up my horseradish sauce. The key is tasting as you go some horseradish is stronger than others. I make this first so the flavors have time to mingle.
- Crostini Time
- My garlic butter brush gives these their incredible flavor. A quick toast in the oven until they're golden and crispy but watch them closely they can burn in seconds.
- Onion Magic
- This is where patience pays off. Low and slow with plenty of stirring transforms plain onions into sweet golden ribbons of happiness. A pinch of sugar is my little secret.
- Putting It All Together
- Assembly is like creating edible art. A schmear of sauce a perfect slice of steak those gorgeous onions and that final drizzle of balsamic glaze makes them absolutely irresistible.
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My Best Tips
I've made these countless times and learned a few tricks along the way. Always let your steak rest or you'll lose all those precious juices. That day old baguette isn't just being thrifty it actually makes better crostini. Don't rush those onions good things take time. And that garlic butter on the bread? Total game changer.
Mix It Up
- Cheese Please: Sometimes I add a tiny slice of blue cheese it gets all melty and wonderful.
- Fresh Herbs: I swap in whatever looks good in my herb garden.
- Extra Heat: A pinch of red pepper in the sauce for spice lovers.
- Veggie Version: Grilled portobello mushrooms make an amazing substitute.
- Switch It Up: When I'm feeling fancy I'll use duck breast instead of steak.
Serving These Beauties
These crostini shine as part of a bigger spread. I love serving them alongside my stuffed mushrooms and tomato bruschetta. A good cabernet brings out the best in the steak and those caramelized onions. Just watch them disappear.
Save It For Later
The beauty of these is you can prep most components ahead. I keep everything separate in the fridge the sauce actually gets better overnight. Just warm the steak gently when you need it and give those crostini a quick toast to crisp them up. Always assemble right before serving that's the secret to perfect texture every time.
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Frequently Asked Questions
- → Can I make this ahead?
Make sauce, onions, and toast bread ahead. Grill steak and assemble just before serving to prevent soggy bread.
- → What's the best steak temperature?
For crostini, medium-rare (125°F) works best. The thin slices stay tender and flavorful.
- → Can I use different bread?
Day-old baguette works best as it's sturdy enough to hold toppings. Sourdough or ciabatta also work well.
- → How do I slice the steak?
Let steak rest 10 minutes, then slice thinly against the grain for most tender bites.
- → Can I substitute the horseradish?
Try garlic aioli or herb mayo instead. The sauce should be creamy with some bite to complement the steak.
Conclusion
An elegant and easy-to-prepare appetizer that combines the richness of grilled steak with the tangy kick of horseradish sauce, perfect for entertaining.