This steak crostini with onion confit and horseradish cream is perfect for parties!
Steak Crostini with Onion Confit and Horseradish Cream
March Madness has finally arrived! Have you picked your favorite team to win? This is an incredibly fun time of year for fans of college basketball. The excitement of spring, brackets, get togethers, friendly rivalries, and good food all make March a time for joyful celebrations. This is a perfect time to gather your friends and family together to enjoy some tasty nibbles while watching the tournament unfold.
Will you be hosting a party this year? If so, have you planned your menu yet? You can never go wrong with classic dishes like wings or nachos, but why not elevate things a bit? This steak crostini with onion confit and horseradish cream is an elegant party snack that will satisfy everyone!

Steak Crostini with Onion Confit and Horseradish Cream
Ingredients
- 1/3 cup extra virgin olive oil
- 1/3 cup red wine vinegar
- 1/4 cup soy sauce
- 1 garlic clove, crushed
- 1 pound flank steak
- 8 ounces sour cream
- 1 tablespoon dijon mustard
- 2 tablespoons horseradish
- 1/2 teaspoon kosher salt
- 1 baguette
- 3 tablespoons extra virgin olive oil, divided
- 2 large yellow onions, chopped
- 3 serrano peppers
- salt and pepper
Instructions
- Prepare the marinade: combine the olive oil, red wine vinegar, soy sauce, and garlic. Trim and discard any fat from the steak and place it in a resealable plastic bag along with the marinade. Refrigerate for at least 4 hours or preferably overnight.
- Whisk together the sour cream, dijon mustard, horseradish and salt. Set aside.
- Preheat the oven to 350 degrees F. Thinly slice the baguette on a slight bias and brush with 1 tablespoon olive oil. Sprinkle with salt. Bake for 10-15 minutes, or until crunchy. Set aside.
- Heat 2 tablespoons olive oil in a large skillet on low heat. Add onions and a pinch of salt. Have a measuring cup full of water nearby. Cook the onions on low heat, stirring frequently, until the onions begin to brown. Turn up the heat to medium and continue caramelizing the onions. As a glaze develops on the bottom of the pan, add a few tablespoons of water and scrape up the brown bits, incorporating them into the onions. The heat will cause the water to evaporate. Repeat this process for approximately 25-30 minutes, keeping a close eye on the onions to make sure they don't burn. When the onions have turned a dark brown color and are both bitter and sweet in flavor, remove from the heat and set aside.
- Preheat the broiler and place a rack toward the top of the oven. Remove steak from the marinade and pat dry with paper towels. Season generously with salt and pepper then broil for 5-6 minutes per side. Allow the meat to rest for at least 10 minutes, then slice very thin against the grain. Allow some of the juices to drain on paper towels.
- Slice the serrano peppers thinly.
- Spread a thin layer of onion confit on each crostini. Top with a slice of flank steak followed by a dollop of horseradish cream. Place a thin slice of pepper on top. These can be made up to 2 hours before serving.
Please read my full post for additional recipe notes, tips, and serving suggestions!
Nutrition
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This post is part of BlogHer’s March Madness editorial series, made possible by Kettle Brand Chips.
More party recipes:
Savory Simple – Cheesy Baked Jalapeno Poppers
Savory Simple – Parmesan, Rosemary and Thyme Shortbread
Savory Simple – Sweet and Spicy Curried Popcorn
Domestic Fits – Maple Chipotle Wings
Mother Thyme – Avocado Deviled Eggs
Horseradish sounds good, but Bearnaise sauce would be another good option. Great idea for a delicious hors d’oeuvre.