Steak Crostini with Creamy Horseradish Sauce and Caramelized Onions
These delicious steak crostini topped with creamy horseradish sauce and sweet caramelized onions are the perfect appetizer for any occasion, easy to make and utterly impressive.
Ingredients
For the Steak
- 1 pound filet mignon or tenderloin Can substitute with flank steak or sirloin.
- Salt and black pepper To taste
- 2 tablespoons unsalted butter For cooking the shallots
- 1 teaspoon garlic powder
- 1 teaspoon dried thyme
For the Sauce
- ½ cup mayonnaise You can substitute with vegan mayonnaise for a dairy-free option.
- 2 tablespoons horseradish (prepared)
- 1 tablespoon Dijon mustard
- 1 tablespoon lemon juice
- Salt and black pepper To taste
For the Baguette
- Baguette (thinly sliced) Brush with olive oil for toasting.
- Olive oil For brushing
For the Caramelized Shallots
- 2 large shallots (thinly sliced)
- 1 tablespoon balsamic vinegar
- 1 tablespoon brown sugar
- Salt and black pepper To taste
Instructions
Preparation
- Season the steak with salt, black pepper, garlic powder, and dried thyme. Let it rest for at least 30 minutes.
- In a bowl, combine mayonnaise, horseradish, Dijon mustard, and lemon juice. Season with salt and black pepper, and refrigerate.
- Melt butter in a skillet, add shallots, and sauté until softened. Add balsamic vinegar, brown sugar, and seasoning. Cook until caramelized.
Cooking
- Cook the seasoned steak in a skillet over medium-high heat until desired doneness (about 4 minutes per side for medium-rare). Let it rest for 10 minutes.
- Preheat oven to 375°F (190°C). Brush baguette slices with olive oil and toast in the oven for 5–7 minutes until golden.
Assembly
- Slice the rested steak thinly and spread horseradish sauce on each toasted baguette slice.
- Top with steak slices and caramelized shallots, then garnish with fresh thyme or parsley.
- Serve immediately.
Notes
To maintain crispness, avoid topping baguette slices until ready to serve. Leftovers can be stored in airtight containers for up to 2 days.