You ever have one of those bites that just stops conversation? That’s this. This Steak Crostini with Horseradish Sauce & Caramelized Onions is unapologetically rich, bold, and made for moments where only the best will do. Whether you’re hosting a black tie affair or a rowdy holiday bash, these crostini deliver that “oh wow” in one savory little mouthful.
Why You’ll Love This Recipe
- Fancy but fuss-free, looks elegant, tastes elevated, but anyone can make it.
- Make-ahead magic, components can be prepped the day before.
- Flavors that pop, bold beef, creamy zing, and sweet onions all on a crisp bite.
A Peek Into the Pantry
Let’s talk about what makes this beauty shine. The ingredients are few, but every single one pulls its weight.
Ribeye Steak: This is where we start big. Ribeye has that marbled, melt-in-your-mouth thing going. It’s the heart of this dish and trust me, it shows. You can also swap in thinly sliced prime rib for a classic Prime Rib Appetizer Holidays feel.
Baguette: A crisp foundation is non-negotiable. Toasted golden with just enough crunch to contrast the tender toppings. You could also go rogue and try it with sourdough or ciabatta.
Prepared Horseradish: Adds a sharp kick and zing that cuts through the richness of the meat. It’s what keeps this from being just another meat canape.
Sour Cream & Mayo: These team up to mellow out the horseradish and bring a creamy body to the sauce. Kinda like the cool friend who keeps the spicy one in check.
Yellow Onions: Low and slow caramelized until they’re sticky, sweet, and ready to party.
Rosemary & Chives: Aromatics for both the onions and garnish. Rosemary infuses earthiness; chives add freshness right at the end.
Let’s Get to the Sizzle
Alright, aprons on. Here’s how we bring it together.
Step 1: Caramelize the Onions
Slice 2 large yellow onions and toss with olive oil, salt, and rosemary. Pop them in a 375°F oven for 35–45 minutes, stirring every 10 minutes until deep brown and jammy. These onions? They’re your flavor insurance.
Step 2: Cook the Steak
Pat your ribeye dry. Salt it like you mean it. Pan-sear or grill until the crust is golden and the inside’s where you want it medium-rare’s the sweet spot. Rest that beauty at least 10 minutes before slicing paper thin.
Step 3: Whip the Horseradish Sauce
Mix 2 tablespoons prepared horseradish, 1 tablespoon mayo, and 1 tablespoon sour cream. Taste. Add salt and pepper if needed. Want more kick? Don’t be shy—add another dab of horseradish.
Step 4: Toast the Crostini
Slice a baguette thin, lay on a sheet tray, drizzle with olive oil, and toast until golden. Watch them close—nobody likes a burnt base.
Step 5: Assemble
On each crostini: smear sauce, layer steak, tuck in some caramelized onions, and finish with a second little swipe of sauce. Top with fresh chives and flaky salt.
Mistakes to Sidestep
Let’s keep your steak crostini journey stress-free:
- Cutting steak too thick : thin slices are key for a balanced bite.
- Skipping the rest time : the juices need to settle in the steak or you’ll end up with a dry situation.
- Using raw onions : caramelizing is non-negotiable here.
Steak Crostini with Horseradish Sauce & Caramelized Onions
Equipment
- Cast Iron Skillet
- Sheet Tray
Ingredients
Steak
- 2 ribeye steaks (~2.75 lb total) ribeye steaks (bone‑in preferred) season with salt, rest then slice thin
Caramelized Onions
- 2 large yellow onions sliced, slow‑caramelized with rosemary
Horseradish Sauce
- 2 tbsp prepared horseradish
- 1 tbsp mayonnaise
- 1 tbsp sour cream
Other Essentials
- baguette, sliced for crostini base; toast until golden
- olive oil for onions and bread
- fresh rosemary sprigs
- fresh chives (finely chopped) for garnish
- flaky salt for finishing crostini
Instructions
- Pre‑heat oven to 375 °F (190 °C). Pat ribeye steaks dry, salt generously on all sides, and let them sit at room temperature (or briefly uncovered in fridge until cooking) to bring to temp. :contentReference[oaicite:2]{index=2}
- Slice the yellow onions, toss with olive oil, salt and a sprig of rosemary in a baking dish or cast iron pan. Place in cold oven as it preheats, then cook for ~35‑45 minutes, stirring every 10 minutes, until the onions are deep brown, sticky and jammy. :contentReference[oaicite:3]{index=3}
- While onions caramelize, heat a cast iron skillet (or grill) over medium‑high heat. Lightly oil the steaks and sear both sides until a golden crust forms. Use a meat thermometer and transfer to the oven if needed to finish to desired doneness (e.g., ~130 °F / 54 °C for medium‑rare). :contentReference[oaicite:4]{index=4}
- Remove steaks from heat and let rest for at least 10 minutes tented with foil. Then slice very thinly across the grain. :contentReference[oaicite:5]{index=5}
- Meanwhile, slice the baguette thinly, place on a sheet tray, drizzle with olive oil and toast in oven for about 5‑10 minutes until lightly golden. :contentReference[oaicite:6]{index=6}
- In a bowl, combine prepared horseradish, mayonnaise and sour cream. Season with salt and pepper to taste, adjust the horseradish for more kick if desired. :contentReference[oaicite:7]{index=7}
- Assemble the crostini: On each slice of toasted baguette, spread a dollop of horseradish sauce, layer with thinly sliced steak, top with some caramelized onions, and finish with another drizzle of the sauce. Garnish with fresh chives and flaky salt. Serve warm or at room temperature. :contentReference[oaicite:8]{index=8}
Notes
- You can prep the onions and sauce a day ahead to save time.
- Use any preferred steak cut (hanger, flank, sirloin) if ribeye isn’t available. Leftovers work great too.
Smart Little Upgrades
This dish already sings, but here are a few pro moves if you want it to belt a power ballad:
- Use a meat thermometer: Nail the doneness every time medium-rare? You’re golden.
- Add blue cheese: Crumble a touch under the steak for a tangy twist. Adds serious “black tie appetizers” energy.
- Try with pickled shallots: A vinegary hit plays off the richness like a dream.
How to Serve It Just Right
Serve these warm or room temp on a rustic wooden board. Nestle in some cornichons, add sprigs of rosemary, and pour something bubbly. These bites are made for sharing, sipping, and storytelling.
FAQs
What’s the best steak cut for crostini?
Ribeye is the go-to because of its fat and flavor, but sirloin or thinly sliced tenderloin work great too. For a classic prime rib appetizer moment, leftover roast slices beautifully.
Can I prep any of this in advance?
You bet. Caramelize onions a day ahead, make the sauce, and even toast the bread. Just reheat the steak gently or serve at room temp—these make excellent Holiday Crostini Appetizers.
Do I need a meat thermometer?
It’s not required, but it’s your secret weapon. Guesswork’s overrated when you’re aiming for juicy steak perfection. Medium-rare? Hit 130°F and let it rest. You’ll thank yourself.
Can I use another sauce instead of horseradish?
Sure thing! Try garlic aioli, mustard cream, or even a blue cheese sauce for a bolder twist. This recipe is flexible like your stretchy holiday pants.
Serving It With Style
Pair with bubbly, bourbon sours, or a peppery cabernet. Serve alongside other O’dourves Appetizers like smoked salmon bites or stuffed mushrooms, and let the good times roll.
Steak Crostini Done Right
This isn’t just another fancy finger food—it’s a bite of memory-making. Whether you’re hosting or showing up with a tray full of love, these steak crostini with horseradish sauce & caramelized onions bring the kind of magic that lingers long after the last bite. Now go on, set that platter down and watch them vanish.
For extra tips and variations (like swapping the sauce or adding pickled peppers), check out this wonderful external recipe article from Most Hungry. It’s loaded with creative spins to make it truly your own.
