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Easy Steak Crostini with Creamy Horseradish Sauce and Caramelized Onions

Close-up of several steak crostini appetizers topped with creamy cheese and caramelized onions.
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Create impressive party food with this easy recipe for steak crostini. It features tender steak, sweet caramelized onions, and a zesty horseradish cream sauce served on toasted baguette slices.

Ingredients

Scale
  • 1 baguette, sliced into 1/2-inch pieces
  • 2 tablespoons olive oil
  • 1 pound sirloin or flank steak
  • 1 teaspoon kosher salt
  • 1/2 teaspoon black pepper
  • 1 large yellow onion, thinly sliced
  • 1 tablespoon butter
  • 1/2 cup sour cream
  • 2 tablespoons prepared horseradish
  • 1 teaspoon Dijon mustard
  • 1 tablespoon fresh chives, chopped

Instructions

  1. Preheat your oven to 375°F (190°C). Brush the baguette slices lightly with olive oil and arrange them on a baking sheet. Bake for 8 to 10 minutes until lightly golden and crisp. Set aside.
  2. Season the steak with salt and pepper. Heat a skillet over medium-high heat. Sear the steak for 3 to 4 minutes per side for medium-rare. Remove the steak from the skillet and let it rest for 5 minutes before slicing thinly against the grain.
  3. While the steak rests, melt the butter in the same skillet over medium heat. Add the sliced onions and cook slowly, stirring occasionally, for 15 to 20 minutes until they are deeply caramelized and sweet. Remove from heat.
  4. Prepare the horseradish sauce: In a small bowl, whisk together the sour cream, prepared horseradish, and Dijon mustard until smooth. Stir in half of the chopped chives.
  5. Assemble the gourmet bites: Spread a small amount of the horseradish cream onto each toasted baguette slice. Top with a few slices of steak, followed by a small portion of caramelized onions.
  6. Garnish each steak crostini with the remaining fresh chives before serving.

Notes

  • You can prepare the caramelized onions and horseradish sauce up to one day ahead to save time when assembling these elegant finger food appetizers.
  • For a richer flavor, substitute the sour cream in the sauce with crème fraîche or cream cheese.
  • If you do not have a baguette, use thick slices of toasted sourdough bread for a similar effect.

Nutrition

Find it online: https://alchemychef.com/steak-crostini-recipe-easy-appetizers/