If you’ve ever wanted a crowd-pleasing appetizer that combines savory steak, sweet caramelized onions, and a zesty kick, then you’re absolutely going to love this Steak Crostini with Horseradish Cream Recipe. Each bite bursts with rich, robust flavors balanced by the creamy horseradish sauce and crisp toasted baguette slices. It’s the perfect way to impress guests or indulge in a fancy snack that feels special but is surprisingly straightforward to make. This recipe turns simple ingredients into a sophisticated snack, bringing layers of taste and texture together in a way that’s pure magic.

Ingredients You’ll Need

The image shows various ingredients arranged neatly on a white marbled surface. On the left side, there is a large red skirt steak placed on a white plate. Above the steak, there is a clear glass measuring cup with dark soy sauce. To the right, a smaller glass measuring cup contains golden olive oil. Next to the olive oil is a small grey bowl with smooth light brown dijon mustard. Below these, a single clove of garlic sits on the surface. In the center, a small pale green bowl holds light brown horseradish, and nearby a small white bowl has creamy white mayo. At the bottom left, a white bowl is filled with creamy sour cream. On the right side, slices of a baguette are spread out on a white plate. Finally, two whole yellow onions rest on the surface near the sour cream and baguette. Photo taken with an iphone --ar 4:5 --v 7

These ingredients are simple yet essential, each playing a unique role in crafting the perfect harmony of flavors and textures in your Steak Crostini with Horseradish Cream Recipe. From the juicy cut of steak to the tangy horseradish cream, every component is thoughtfully chosen to elevate this dish.

1-1½ lbs hanger steak (skirt steak, or flank steak): Choose a well-marbled cut for the best flavor and tenderness.
⅓ cup soy sauce: Adds a savory, umami depth to the marinade.
¼ cup extra virgin olive oil: Brings richness and helps in caramelizing onions and toasting bread evenly.
2 tablespoons sugar (brown or granulated): Balances out the acidity and aids in caramelizing the onions beautifully.
1 tablespoon apple cider vinegar or balsamic vinegar: Provides a mild tanginess to brighten up the marinade.
½ tablespoon Dijon mustard: Adds subtle spice and emulsifies the marinade.
1 large garlic clove (minced): Infuses a warming, aromatic bite into the steak flavoring.
3 large yellow onions: Keys to that luscious, jammy caramelized onion topping.
2 tablespoons extra virgin olive oil: For slow-cooking the onions to perfect sweetness.
½ cup sour cream: The creamy base of our horseradish sauce that balances heat with smoothness.
½ cup mayonnaise: Adds richness and a velvety texture to the horseradish cream.
2-4 tablespoons prepared horseradish: The star of the sauce that gives a bright, peppery punch.
1 tablespoon apple cider vinegar: Boosts the tang of the horseradish cream.
½ teaspoon kosher salt: Enhances all the layers of flavor throughout.
¼ teaspoon cracked black pepper: Adds a bit of heat and complexity to the sauce.
1 baguette (sliced into ½” pieces, about 20-24 slices): Toasted to crispy perfection, it’s the perfect edible base.
¼ cup extra virgin olive oil: For brushing bread and finishing steak crostini.
1 large garlic clove: Rubbing on toasted bread imparts a subtle garlicky aroma and flavor.
Fresh chives (finely chopped, for garnish): Adds a fresh, mild onion flavor and pretty green color.
Flaky sea salt (for garnish): Delivers a satisfying crunch and highlights all the savory notes.

How to Make Steak Crostini with Horseradish Cream Recipe

Step 1: Marinate the Steak

Start by whisking together soy sauce, olive oil, sugar, vinegar, Dijon mustard, and minced garlic until well combined. Place your hanger steak in a large gallon zip-top bag or a shallow dish and pour the marinade over it. Seal and refrigerate for at least 4 hours, but for the best flavor penetration, aim for closer to 24 hours. This step infuses the meat with savory, slightly sweet notes creating a flavorful crust when cooked.

Step 2: Caramelize the Onions

While the steak marinates, peel, halve, and slice the onions super thin. In a large skillet over medium-low heat, coat the pan with olive oil then add the onions. Toss well to coat, allowing them to soften for about 5 minutes before turning the heat down to the lowest setting. Patience is key here—slowly stir every 5 minutes for about 30-40 minutes as the onions transform into golden, jammy goodness. If they start sticking or burning, splash a little water to help loosen the bits. The result is an irresistibly sweet and deeply flavorful topping for your crostini.

Step 3: Prepare the Horseradish Cream

In a bowl, whisk together sour cream, mayonnaise, horseradish, apple cider vinegar, kosher salt, and cracked black pepper. Taste and adjust seasoning to your liking. This creamy concoction adds a thrilling spicy brightness that cuts through the richness of the steak perfectly. Cover and chill until ready to serve.

Step 4: Toast the Baguette

Slice your baguette at a slight angle into half-inch pieces and arrange them on a baking sheet. Generously brush the tops with olive oil and broil in your oven, keeping a close watch, until golden and crisp. Flip the slices and broil the other side to match. When out of the oven, rub the toasted bread with the cut side of a peeled garlic clove for an aromatic touch that takes the crostini to the next level.

Step 5: Cook the Steak

Remove the steak from the marinade and pat it dry to ensure a nice sear. Heat a cast iron skillet or grill pan on medium-high heat and add a bit of olive oil. Sear the steak for 2-3 minutes per side without moving it to develop a beautiful crust. Continue flipping until your desired doneness is reached—rare at 120℉, medium rare at 130℉, or medium at 140℉. Avoid cooking beyond medium to keep the steak tender and juicy. Let it rest 10-15 minutes before slicing thinly against the grain.

Step 6: Assemble the Crostini

Arrange your toasts on a platter, then layer on a spoonful of those luscious caramelized onions. Add a few strips of the sliced steak and dollop generously with horseradish cream. Finish each crostini with a sprinkle of fresh chives and flaky sea salt for bursts of flavor and a lovely presentation.

How to Serve Steak Crostini with Horseradish Cream Recipe

The image shows many small, golden-brown toasted bread slices spread out on a slightly worn metal baking tray, each slice with a crisp texture and light browning. A woman's hand with two simple rings gently rubs a clove of garlic over one toast, adding a natural, warm touch to the scene. The toasts have uneven shapes with some holes and a crunchy look, all resting on the cool metal tray surface. photo taken with an iphone --ar 4:5 --v 7

Garnishes

Fresh chives and flaky sea salt aren’t just decorative—they add a subtle freshness and delightful texture contrast that complements the rich steak and creamy sauce. You can also experiment with microgreens or thinly sliced radishes for added color and crunch.

Side Dishes

This Steak Crostini pairs wonderfully with a simple mixed greens salad dressed lightly with lemon vinaigrette to cut through the richness. Roasted seasonal vegetables or a crisp, cold white wine are also fantastic companions that round out this indulgent appetizer or light meal.

Creative Ways to Present

Lay the crostini on a rustic wooden board for a casual vibe or arrange them neatly on a sleek platter for a classy party spread. For an extra special touch, serve with small bowls of horseradish cream on the side so everyone can add more spice if they dare. Beautifully fresh herbs scattered around the serving dish create an inviting, Instagram-worthy display.

Make Ahead and Storage

Storing Leftovers

Keep any leftover steak slices, horseradish cream, and caramelized onions stored separately in airtight containers in the refrigerator. The toasted baguette is best eaten fresh but can be kept for a day or two if loosely wrapped. This way, your components stay fresh and ready for a quick reassembly.

Freezing

While it’s not ideal to freeze the assembled crostini because the baguette will lose crispness, you can freeze the cooked steak and caramelized onions separately for up to 2 months. Thaw in the refrigerator overnight and reheat gently for best results.

Reheating

Warm the steak gently in a skillet or microwave to avoid overcooking, and reheat onions on low heat. Toast the baguette slices again briefly to regain crispness. Add fresh horseradish cream afterward for that cool, creamy finish.

FAQs

Can I use other cuts of steak for this recipe?

Absolutely! While hanger, skirt, or flank steaks are ideal for their flavor and texture, you can also use ribeye or sirloin if that’s what you have on hand. Just adjust cooking times to prevent overcooking.

How spicy is the horseradish cream?

The heat level depends on how much prepared horseradish you use. The recipe’s range of 2-4 tablespoons allows you to customize from mildly tangy to boldly spicy. Start with less and add more after tasting if desired.

Can I prepare the caramelized onions in advance?

Yes! Caramelized onions keep beautifully in the refrigerator for up to 5 days. Making them ahead saves you a lot of time when assembling your crostini, and their flavor only deepens with time.

What’s the best way to slice the steak for crostini?

Slicing the steak thinly against the grain at about a 45-degree angle ensures the meat is tender and easy to bite. Thin slices also help the steak balance perfectly with the toppings and bread.

Is this recipe suitable for entertaining a large group?

Definitely! The Steak Crostini with Horseradish Cream Recipe yields about 16 servings, making it perfect for parties and gatherings. It’s easy to scale up and the make-ahead components mean less stress on the day of your event.

Final Thoughts

This Steak Crostini with Horseradish Cream Recipe is truly one of those dishes that feels fancy but delivers comfort with every bite. Whether you’re hosting friends or simply treating yourself, it’s a delicious way to elevate simple ingredients into something unforgettable. I can’t recommend it enough—go ahead and make it your new favorite appetizer, you won’t regret it!