These steak crostini with horseradish sauce are perfect little bites that are incredibly delicious and super easy to make. They’re also a fantastic option for feeding a crowd since one steak can stretch to make lots and lots of crostini.
I originally made these for Christmas, but they’re certainly not limited to special occasions. You can transform the recipe into a sandwich or tartine for more of a full meal. The combination of perfectly cooked ribeye, creamy horseradish sauce, and caramelized onions is good anyway you put them together, so do what works for you.
These steak and horseradish crostini are a low-effort appetizer where everything can be prepared ahead of time and served at room temperature. We love a low-stress hors d’oeuvre!
An Easy and Delicious Appetizer for Entertaining
These steak and horseradish crostini are a low-effort appetizer where everything can be prepared ahead of time and served at room temperature. We love a low-stress hors d’oeuvre!
For this recipe, I used ribeye because I wanted a cut with lots of flavor and great marbling. That said, you can absolutely swap it out for your preferred cut. Filet, hanger steak, thinly sliced rib roast, or skirt steak would all work perfectly. To sauce the crostini, I whipped up a quick horseradish cream sauce that comes together in minutes and adds the perfect touch of spice to complement the beef. And I can’t forget to mention the caramelized onions! I cooked these in the oven while the ribeyes were grilling, and the sticky-sweet onions are a must for this recipe.
Okay, enough with the intro—let’s get to the recipe below!
Ingredients You’ll Need
- Ribeye Steaks – I like ribeye for it’s flavor and good amount of fat. I like beefy beef. Other cuts that work well include hanger steak, skirt steak, or sirloin. And if you wanted something more mild stick with a filet, strip steak or rib roast. Use whatever cut you like and enjoy the flavor of!
- Baguette – This serves as the base for our crostini, but feel free to use any bread you like. Ciabatta, sourdough, or even pumpernickel would all work beautifully here.
- Horseradish – Prepared horseradish is what this recipe calls for, but if you can get fresh use that! You’ll only need about half the amount since fresh horseradish is much punchier and spicier. Adjust the quantity to your taste.
- Onions – Yellow or white onions are great here, and if you can get a sweet onion, even better. The onions are slowly cooked until they become sweet, sticky, and caramelized.
- Rosemary – Fresh rosemary adds wonderful flavor to the the onions and the ribeye. You can also use fresh thyme if you like.
- Chives – Finely chopped fresh chives bring a welcome pop of color to the final steak crostini and provide a mild onion flavor that complements the dish perfectly.
- Mayo – Mayonnaise serves as the base for the horseradish cream sauce. Use your favorite mayo; I recommend Hellmann’s or Kewpie.
- Sour Cream – Full-fat sour cream is ideal here. It adds the creamy consistency we want in the horseradish sauce for a delicious, tangy finish.
- Olive Oil – Or any other neutral oil you like. You need a little to coat the ribeyes before either grilling or searing.
- Butter – Adds some extra richness to the steaks
- Salt – Diamond Crystal Kosher salt is what I recommend.
How To Make These Crostini
Prep The Steaks
Start by patting you steaks dry and season them liberally with salt on all sides. (more on how to properly salt steak is below) Place the steaks on a baking tray fitted with a rack and let them sit uncovered in the fridge until you’re ready to grill. You want the steaks to come to room temperature before cooking, this typically takes about an hour, so plan accordingly. If you’re cooking them right away, there’s no need to refrigerate.
Make Horseradish Sauce
To make the sauce, combine prepared horseradish, mayonnaise, and sour cream in a bowl and mix. Season with salt and pepper to taste, then set aside.
Make Caramelized Onions
Add your sliced onions to a cast iron pan or baking dish. Toss them with a generous bit of olive oil and a pinch of salt, then add a sprig of rosemary. Place the onions into a cold oven to begin cooking as your oven preheats to 375°F.
After about 20 minutes, give those onions a toss. Continue tossing every 10 minutes or so until they are a dark brown, sticky and caramelized. It will take about 35–45 minutes in total.
Cook Steaks
Preheat your oven to 375°F.
Depending on how you want to cook your steaks, heat either a grill or cast iron pan, over medium-high heat. Pay steaks dry, then lightly oil them and cook on both sides until nicely browned.
Using a meat thermometer, check the internal temperature of the steaks. Transfer them to the 375°F oven to finish cooking, checking the temperature every 5 minutes until they reach your desired doneness. (Here is a helpful chart for Steak Doneness Temperatures) Don’t forget to give the onions another toss while the steaks cook.
Once the steaks are cooked to your liking, remove them from the oven. Top each steak with butter and a few sprigs of rosemary. Cover with aluminum foil and let them rest for at least 10 minutes before slicing into them.
Toast Baguette
Slice your baguette and toast the pieces in the oven for about 5–10 minutes until lightly golden.
Assemble Crostini
To assemble the crostini, arrange the toasted baguette slices on your serving platter. Top each slice with a dollop of the horseradish cream sauce, a layer of very thinly sliced ribeye, those caramelized onions, and another drizzle of the sauce. Finish with a sprinkle of fresh chives and some flaky salt.
Serve with lots of little cornichons on the side, and eat up!
Some Essential Tips and Tricks to Cooking Steak
What Type of Steak Should You Use?
I used bone in ribeye here. It’s a pretty flavorful cut with lots of fat. Other cuts that would be equally delicious include hanger steak, skirt steak, sirloin, filet, strip steak or even a rib roast if you’re making this for a big crowd. Use whatever cut you like and enjoy the flavor of!
How to Properly Temp your steak
Getting a steak cooked to your desired doneness can be tricky. There are many factors that go into cooking a steak, and simply guessing whether you’ve hit medium-rare, rare, or well-done doesn’t always work. There’s no glory in blindly guessing and hoping you’ve nailed the correct temperature. That’s why I highly recommend using a meat thermometer.
A digital quick-read thermometer is a great investment (Escali Folding Digital Thermometer). You’ll find yourself using it for much more than just cooking steak, and it removes so much unnecessary guesswork—and stress—from the process.
Below are the doneness levels and temperatures you want to aim for. Keep in mind that there’s always carryover cooking, meaning the temperature will continue to rise a few degrees as the steak rests. To account for this, make sure to check and remove the steak from the heat before it reaches your ideal temperature.
Steak Doneness Temperatures:
- Rare: 120°F / 49°C (pull from heat at 118°F / 48°C)
- Medium-Rare: 130°F / 54°C (pull from heat at 125°F / 52°C)
- Medium: 140°F / 60°C (pull from heat at 135°F / 57°C)
- Medium-Well: 150°F / 66°C (pull from heat at 145°F / 63°C)
- Well-Done: 160°F / 71°C (pull from heat at 155°F / 68°C)
Let the meat rest for 5-10 minutes before slicing into it. It’ll help redistribute the juices and let the meat relax. It’ll be much nicer biting into a properly rested steak.
How to properly salt your steaks
Just like cooking steak to a specific doneness can be a bit daunting, so can salting a steak. For a steak to taste as delicious as it possibly can, it needs to be well-seasoned. I like to use Diamond Crystal kosher salt, and if you’re not using it, I highly recommend it. Its loose, coarse texture makes it easy to achieve an even coating when you sprinkle it from a height.
As a general rule of thumb, aim for about 1–1.5% salt by weight. Yes, you’ll need a digital scale for this (I recommend the Escali Primo Digital Scale). Weigh your steaks and then weigh out your salt. For boneless steaks, use 1% salt; for bone-in steaks, use 1.5% salt. For instance, if you have 1200g of boneless steak, you’ll need 12g of salt.
Some Variations on This Recipe
Arugula and Shredded Parmesan
Add shards of Parmigiano Reggiano and fresh arugula. This combination creates such a fantastic balance of flavors.
Add Pickled Peppers
Incorporate pickled peppers like Peppadews, pepperoncini, or banana peppers. The spice and vinegary tang pair beautifully with the steak. You can either place a slice on top of each crostini or chop the peppers and stir them into the horseradish sauce for an extra kick.
Blue Cheese Dressing
Not a fan of horseradish? Try making a blue cheese dressing instead. (I have a great blue cheese dressing recipe to check out!) Simply swap out the horseradish for crumbled blue cheese in this recipe, and you’ll have a rich and flavorful sauce. Adding a little fresh tarragon would also be a delightful touch.
What to do with any leftover horseradish sauce
You could use this horseradish sauce for fish, served alongside a beef tenderloin, prime rib, or even simple as a dip for some crudité or even just on an oyster cracker. This sauce also goes very well with crab. Either as a dip, or as a sauce for a crab salad.
Recommended Equipment:
Thermometer: Escali Folding Digital Thermometer
Digital Scale: Escali Primo Digital Scale
Did you make this recipe?
Did you try this Steak Crostini Recipe? Leave a comment below with your thoughts or share your version on Instagram by tagging @TheMostHungry. I’d love to see how you made it your own!
Steak Crostini with Horseradish Sauce and Caramelized Onions
Equipment
Ingredients
For The Steaks
- 2 ribeye steaks bone in, ~2.75lb
- salt 1% - 1.5% weight of steaks
- 1-2 tbsp butter
- 2 sprigs rosemary
The Caramelized Onions
- 2 large onions yellow or white, sliced
- 1 sprig rosemary
Horseradish Cream Sauce
- 2 tbsp prepared horseradish
- 1 tbsp mayonnaise
- 1 tbsp sour cream
Other Essentials
- olive oil
- salt
- pepper
To Serve
- 1 baguette sliced
- chives finely sliced
- cornichon
- flakey salt
Instructions
Prep The Steaks
- Pat the steaks dry and season them with salt on all sides. Place the steaks on a tray fitted with a rack and let them sit uncovered in the fridge until you’re ready to cook. The steaks should come to room temperature before cooking, which typically takes about an hour, so plan accordingly. If you’re cooking them right away, there’s no need to refrigerate.
Make Horseradish Sauce
- In a bowl, combine prepared horseradish, mayonnaise, and sour cream. Season with salt and pepper to taste, then set aside.
Make Caramelized Onions
- Add sliced onions to a cast iron pan or baking dish. Toss them with oil and a pinch of salt, then add a sprig of rosemary. Place the onions into a cold oven to begin cooking as the oven preheats to 375°F.
- After about 20 minutes, give the onions a toss. Continue tossing every 10 minutes or so until they are dark brown and caramelized, which will take about 35–45 minutes in total.
Cook Steaks
- Preheat your oven to 375°F.
- Heat a grill or cast iron pan over medium-high heat. Lightly oil the steaks and cook them on both sides until nicely browned.
- Use a meat thermometer to check the internal temperature of the steaks. Transfer them to the oven to finish cooking, checking the temperature every 5 minutes until they reach your desired doneness. Don’t forget to give the onions another toss while the steaks cook.
- Once the steaks are cooked to your liking, remove them from the oven. Top each steak with a pat of butter and a few sprigs of rosemary. Cover with aluminum foil and let them rest for at least 10 minutes before slicing.
Toast Baguette
- Slice the baguette and toast the pieces in the oven for 5–10 minutes until lightly golden.
Assemble Crostini
- To assemble the crostini, arrange the toasted baguette slices on a serving platter. Top each slice with a dollop of horseradish cream sauce, a layer of very thinly sliced steak, caramelized onions, and another drizzle of the sauce. Finish with a sprinkle of fresh chives and flaky salt.
- Serve with cornichons on the side, and eat up!
Did You Make This Recipe?
Leave a comment with your thoughts or share your version on Instagram by tagging @TheMostHungry. I’d love to see how you made it your own!
