Seared Steak Crostini Recipe with Garlic Herb Butter

This Steak Crostini recipe makes a savory, crowd-pleasing appetizer: seasoned top sirloin cooked sous vide (or grilled), thinly sliced and served on toasted baguette slices with a creamy horseradish goat cheese spread. Finish each crostini with a drizzle of balsamic reduction and fresh basil for bold, balanced flavor.

If you want an elegant party starter or a flavorful snack, steak crostini deliver every time. The combination of tender, evenly cooked steak with tangy, creamy horseradish goat cheese and a sweet-tart balsamic reduction creates excellent contrast in each bite. This recipe uses top sirloin prepared sous vide for consistent doneness and tender texture, though you can easily substitute a grill or hot skillet if you prefer.

Ingredients

• Top sirloin steak – about 2 pounds total, ideally 1½ inches thick (use 2–4 steaks depending on size).
• Olive oil – or a neutral oil such as canola or avocado oil.
• Garlic – 2–3 cloves, crushed or finely chopped.
• Red pepper flakes, salt, and black pepper – to taste for seasoning the steak.
• Fresh rosemary – chopped, for aromatics in the bag (dried rosemary can be used if needed).
• Baguette – a French or sourdough baguette, sliced into rounds.
• Olive oil cooking spray – or brush slices with olive oil before toasting.
• Goat cheese – about 8 ounces.
• Horseradish cream – about 2 tablespoons, folded into the goat cheese to taste.
• Balsamic reduction – store-bought or homemade balsamic glaze to drizzle on top.
• Fresh basil – chopped, for garnish.

Instructions

Below are clear, step-by-step instructions for making steak crostini. The recipe is flexible: sous vide yields reliably tender results, while grilling works well for a more classic charred finish.

Cook the steaks in a sous vide

1. Place the steaks into a vacuum-seal bag or a heavy-duty, freezer-grade zipper bag. Add 1/3 cup olive oil, crushed garlic, 1/2 teaspoon red pepper flakes, 2 teaspoons salt, 1 tablespoon black pepper, and 1 tablespoon chopped fresh rosemary.
2. Seal the bag. If you don’t have a vacuum sealer, use the water-displacement method with a zipper bag: seal most of the bag, then slowly lower it into water so pressure expels the air before closing the bag completely.
3. Fully submerge the sealed bag in a water bath and attach your sous vide circulator. Set the temperature to 131°F for medium-rare and cook the steaks for 4–8 hours. The beauty of sous vide is precision and forgiveness: a longer cook within that window produces the same doneness and extra tenderness.
4. When the steaks are done, remove the bag from the water, open it, and use tongs to transfer the steaks to a plate. Pat dry with paper towels if you plan to sear in a skillet.
5. Preheat a cast-iron skillet or grill to very high heat. Sear the steaks 30–60 seconds per side just to develop color and a crust.
6. Transfer to a cutting board and allow the steaks to rest for 10 minutes before slicing thinly against the grain.

Prepare the crostini

1. Preheat the oven to 375°F. Slice the baguette into rounds and arrange them on a baking sheet.
2. Lightly spray or brush the baguette slices with olive oil and toast in the oven 3–5 minutes, until golden and crisp. Remove and cool slightly.
3. In a small bowl, combine 8 ounces goat cheese with about 2 tablespoons horseradish cream, adjusting the ratio to taste until smooth and spreadable.
4. Spread a thin layer of the horseradish goat cheese on each toasted baguette slice.
5. Top each piece with a few thin slices of the rested steak. Drizzle with balsamic reduction and finish with chopped fresh basil.
6. Serve immediately while the bread is crisp and the steak is warm.

How to cook the steak on a grill

If you don’t have a sous vide, grill the steaks instead. Marinate or season as above, then grill over high heat until an instant-read thermometer reads 130–135°F for medium-rare. Let the steaks rest for 10 minutes, slice thin, and continue with the crostini assembly.

Recipe substitutions

• Other cuts: Filet mignon or ribeye can be used in place of top sirloin for a more tender or richer result.
• Cheese variations: Swap the horseradish goat cheese for a blue cheese spread (mix 8 ounces blue cheese with 2 tablespoons blue cheese dressing) or a cream cheese base with horseradish mixed in.
• Herb options: Thyme or oregano can replace rosemary for a different aromatic profile.

Frequently asked questions

• What does sous vide do? Sous vide cooks food sealed in a bag immersed in a precisely controlled water bath. It produces perfectly even doneness edge-to-edge and preserves juices and flavor, which is especially useful for steak.
• Are zipper bags safe for sous vide? Heavy-duty freezer-grade zipper bags are commonly used and are safe at typical sous vide temperatures (well below the softening point of most good-quality bags).
• Can you sous vide steak from frozen? Yes. You can cook steaks straight from the freezer; allow at least 2 hours in the water bath, and adjust time depending on thickness.
• Why sear after sous vide? Searing adds color, texture and a caramelized crust that improves flavor and presentation, even though the steak is already cooked through by the sous vide.

Sous vide steak temperature chart

• Rare: 120–128°F
• Medium-rare (recommended): 129–134°F
• Medium: 135–144°F
• Medium-well: 145–155°F
• Well-done: 156–162°F