Name: Grilled Steak Crostini with Horseradish Sauce Recipe
Prep time: 20 min
Cook time: 20 min
Total time: 40 min
Cuisine: American
Ingredients: 8 ounces Filet Mignon Steaks; 2 tablespoons olive oil (optional); 2 tablespoons steak seasoning; 1 cup sour cream; 1/4 cup prepared horseradish; 1 1/2 tablespoons Dijon mustard; 1 teaspoon champagne vinegar; 1 teaspoon Worcestershire sauce; 1/2 tablespoon fresh chopped chives; Salt and pepper to taste; 1 day-old baguette, cut into 1/4 inch slices; 2 tablespoons butter, melted; 1/4 cup olive oil; 1 garlic clove, smashed (optional); 1 onion, diced; 1 tablespoon olive oil; 1/2 tablespoon butter; 1/4 teaspoon sugar; Kosher salt to taste; Chopped fresh chives (optional); Balsamic glaze (optional)

If you’re on the lookout for a sophisticated yet surprisingly simple appetizer that’s sure to impress your guests, the Grilled Steak Crostini with Horseradish Sauce Recipe is a must-try. Imagine tender, juicy slices of grilled filet mignon layered on perfectly toasted baguette rounds, crowned with sweetly caramelized onions and a zingy, creamy horseradish sauce that delivers a beautiful punch of flavor. This dish strikes such a wonderful balance of textures and tastes — crispy, creamy, savory, and just a touch tangy, making it an irresistible bite every single time.

Ingredients You’ll Need

The image shows two round pieces of raw meat on a white square plate. Each piece is covered with a layer of crushed black pepper and yellow seasoning mixed with salt, evenly spread on top. The plate sits on a woven brown mat, and there is a silver fork with a blue handle placed to the right side of the meat on the plate. The background is a white marbled surface. photo taken with an iphone --ar 4:5 --v 7

This recipe calls for a handful of straightforward ingredients that come together to create an unforgettable flavor profile. Each component contributes uniquely — the quality of the steak lends richness, the crostini bring that satisfying crunch, while the horseradish sauce and caramelized onions add layers of excitement and brightness.

8 ounces Filet Mignon Steaks: Choose tender, prime cuts for the best texture and flavor.
2 tablespoons olive oil: Optional but great for enhancing the steak’s sear and caramelization.
2 tablespoons Steak Seasoning: Adds essential seasoning that complements the beef perfectly.
1 cup sour cream: Provides a creamy, tangy base for the horseradish sauce.
1/4 cup prepared horseradish: Offers that signature kick that cuts through the richness.
1 1/2 tablespoons dijon mustard: Brings subtle heat and depth to the sauce.
1 teaspoon champagne vinegar: Adds brightness and balances the creaminess.
1 teaspoon Worcestershire sauce: Delivers umami and complexity.
1/2 tablespoon fresh chopped chives: For a pop of fresh herby flavor.
Salt and pepper to taste: Essential for seasoning every element.
1 Day old baguette: Cut into 1/4 inch slices for perfect crostini texture.
2 tablespoons melted butter: Helps achieve a golden, buttery toast.
1/4 cup olive oil: Adds crispness and extra flavor to the crostini.
1 garlic clove smashed (optional): Infuses the oil with subtle garlic aroma.
1 onion diced: The star of the sweet, caramelized onion topping.
1 tablespoon olive oil: For gently softening and caramelizing onions.
1/2 tablespoon butter: Enhances richness in the onions.
1/4 teaspoon sugar: Helps the onions caramelize perfectly by balancing acidity.
Kosher salt to taste: Enhances flavors throughout your dish.
Chopped fresh chives (optional): For garnish and fresh color.
Balsamic glaze (optional): Adds a sweet tangy drizzle that finishes the crostini beautifully.

TIP

You’ll find the full ingredient list, instructions, and print option in the recipe card below.

How to Make Grilled Steak Crostini with Horseradish Sauce Recipe

Step 1: Preparing and Grilling the Steaks

Start by preheating your grill to a hot 450 degrees. This high heat is key to achieving that perfect crust on the filet mignon. Season the steaks generously with kosher salt and freshly ground pepper. Grill the steaks for about 4 to 5 minutes on the first side without flipping prematurely to allow a beautiful sear to develop. Flip and grill for another 4 to 5 minutes, or until you reach your desired doneness — medium rare is ideal to keep the meat tender and juicy. Once cooked, rest the steaks on a platter covered with foil for about 10 minutes to let the juices redistribute. This step ensures every bite is bursting with flavor.

Step 2: Whisking Up the Horseradish Sauce

While your steak rests, combine sour cream, prepared horseradish, dijon mustard, champagne vinegar, Worcestershire sauce, salt, pepper, and freshly chopped chives in a bowl. Whisk until smooth and creamy. This sauce is the star accompaniment that adds a wonderful zingy creaminess to balance the richness of the steak and buttery crostini.

Step 3: Toasting the Crostini

Preheat your oven to 375 degrees F. Slice your day-old baguette into 1/4 inch rounds — using day-old bread makes for crunchier crostini that hold up well under toppings. Mix melted butter, olive oil, and smashed garlic in a bowl, then brush generously on both sides of each slice. Place them on a baking sheet and toast for about 5 minutes, then flip and toast another 3 to 4 minutes until golden and crispy. Let the crostini cool at room temperature to maintain their crispness.

Step 4: Caramelizing the Onions

In a skillet over medium-high heat, warm olive oil and butter together. Add diced onions and a pinch of kosher salt to coax out their natural sweetness. Let the onions cook slowly, stirring occasionally, until they transform into deeply golden, tender morsels — this can take 15 to 20 minutes. Sprinkle sugar to encourage caramelization and cook for a few more minutes before seasoning with salt to taste. These onions bring a beautifully sweet counterpoint to the peppery steak and zesty sauce.

Step 5: Assembling Your Grilled Steak Crostini with Horseradish Sauce Recipe

Spread about a teaspoon of the horseradish sauce onto each crostini round. Thinly slice your rested steak against the grain for tenderness and layer each piece on top of the sauced bread. Add half a tablespoon of the caramelized onions to each assembled crostini. Garnish with chopped fresh chives and drizzle with balsamic glaze if you love a touch of balsamic’s sweet acidity. Serve immediately to enjoy the perfect marriage of crisp, creamy, savory, and sweet flavors.

How to Serve Grilled Steak Crostini with Horseradish Sauce Recipe

Two pieces of dark brown grilled meat with charred black spots lie on a clean white rectangular plate, with a small pool of brown juice around them. Next to the plate, a silver metal tray holds many slices of toasted bread that are golden brown with some darker grill marks. The scene is set on a white marbled surface with a small piece of colorful cloth peeking from underneath the plate. Photo taken with an iphone --ar 4:5 --v 7

Garnishes

Fresh, bright garnishes elevate this dish beautifully. Chopped fresh chives add a mild oniony freshness while a drizzle of balsamic glaze introduces a glossy, tart-sweet finish. If you’re feeling adventurous, sprinkle some cracked black pepper or a dusting of smoked paprika for an extra flavor boost.

Side Dishes

This dish shines as a stand-alone appetizer or party snack but pairs wonderfully with a crisp green salad dressed in lemon vinaigrette, roasted baby vegetables, or even a chilled glass of crisp white wine like Sauvignon Blanc or a peppery red such as Pinot Noir. These sides keep the meal balanced and fresh.

Creative Ways to Present

Transform your serving style by placing crostini on a long wooden board with spreading bowls of the horseradish sauce and caramelized onions for a beautiful DIY experience. Or arrange the crostini on a tiered serving platter for an elegant party display that invites guests to indulge. For casual gatherings, a rustic tray lined with parchment paper adds cozy charm.

Make Ahead and Storage

Storing Leftovers

If you have any leftover steak, crostini, or toppings, store them separately in airtight containers in the refrigerator. This keeps each component fresh and prevents sogginess, especially in the crostini. Use leftovers within 2 days for best flavor.

Freezing

While the components of this Grilled Steak Crostini with Horseradish Sauce Recipe are best enjoyed fresh, you can freeze cooked steak wrapped tightly in foil or plastic wrap. Avoid freezing crostini or caramelized onions as their textures change. Thaw steak gently in the fridge before reheating.

Reheating

Reheat leftover steak quickly in a hot skillet or under the broiler for just a minute or two to maintain juiciness. Warm caramelized onions gently on the stove, and re-toast any crostini in the oven to restore crispness. Add horseradish sauce fresh to keep the bright flavor intact.

FAQs

Can I use a different cut of steak for this recipe?

Absolutely! While filet mignon is recommended for tenderness and flavor, sirloin or ribeye can also work well. Just adjust grilling times accordingly to your preferred doneness and steak thickness.

Is there a vegetarian alternative to steak in this recipe?

Yes! Consider using grilled portobello mushrooms or marinated grilled tofu as a replacement. They absorb flavors beautifully and pair nicely with the horseradish sauce and caramelized onions.

How spicy is the horseradish sauce?

The horseradish adds a moderate heat and sharpness that livens up the crostini without overwhelming. You can adjust the amount of prepared horseradish to make it milder or stronger depending on your taste.

Can I make the horseradish sauce ahead of time?

Yes, you can prepare the horseradish sauce a day in advance. Store it in an airtight container in the fridge and give it a good stir before assembling the crostini.

What type of bread works best for the crostini?

A day-old baguette is ideal because it crisps up nicely without becoming too hard. If baguette isn’t available, a rustic Italian or French bread sliced thinly will also do the trick.

Final Thoughts

This Grilled Steak Crostini with Horseradish Sauce Recipe is truly one of those dishes that feels special but is wonderfully approachable to make. Whether you’re hosting a party, looking for an elegant snack, or simply craving something packed with flavor, these crostini check all the boxes. I can’t wait for you to try this recipe and share the joy it brings with friends and family — it’s sure to become a favorite in your culinary lineup!