Juicy Roast Beef Crostini

Here’s my go-to roast beef crostini recipe, featuring crispy toasted baguette slices topped with tender roast beef, fresh herbs, and a simple horseradish cream that adds just the right kick.

These crostini are my favorite party appetizer – they always disappear within minutes when I serve them at gatherings. I usually make an extra batch to keep in the kitchen because my family sneaks them before the guests arrive!

What Kind of Roast Beef Should I Use?

For crostini, you’ll want to look for high-quality, thinly sliced deli roast beef rather than cooking a roast from scratch. The best options are medium-rare roast beef sliced paper-thin – either top round or beef tenderloin work great here. If you’re shopping at the deli counter, ask them to slice it as thin as possible (almost shaved), which makes it easier to bite through and creates a better texture on the crostini. While you can use pre-packaged roast beef from the grocery store, freshly sliced from the deli counter typically has better flavor and texture. Just make sure to bring the roast beef to room temperature before assembling your crostini, as cold meat won’t taste as flavorful.

Options for Substitutions

This crostini recipe is pretty adaptable and you can make several swaps based on what you have in your kitchen:

• Baguette: While baguette is ideal for crostini, you can use ciabatta or any crusty bread cut into small pieces. Just make sure it’s fresh and can hold up to toppings.
• Horseradish sauce: If you’re not a fan of horseradish or can’t find it, try Dijon mustard instead. Start with 1 tablespoon and adjust to taste.
• Mayo and sour cream: Greek yogurt can replace either the mayo or sour cream (or both). You might need to add a bit more lemon juice to match the tanginess.
• Roast beef: Leftover steak, sliced thin, works great here. You could also use rare roast turkey or even smoked duck for a fancy twist.
• Balsamic reduction: Regular balsamic vinegar reduced in a pan works, or you can use a drizzle of honey mixed with regular balsamic vinegar. Fig jam is another nice option.
• Micro/baby arugula: Any tender greens will work – try watercress, baby spinach, or even finely chopped regular arugula. Each brings its own pepper kick to the dish.
• Pomegranate seeds: These add a nice crunch and color, but you can skip them or swap with finely diced red bell pepper or cherry tomatoes for that pop of color.

Watch Out for These Mistakes While Cooking

The biggest challenge when making crostini is getting the bread texture just right – slicing your baguette too thick will make it hard to bite through, while too thin will cause it to burn quickly, so aim for about 1/2-inch thickness and watch them closely while toasting.

A common error is spreading too much horseradish mixture on each piece, which can overpower the other flavors – instead, use about 1-2 teaspoons per crostini and make sure to spread it evenly.

When assembling, avoid the mistake of preparing these too far in advance, as the bread can become soggy from the toppings – instead, toast your bread slices up to 4 hours ahead, but wait to add the toppings until 30 minutes before serving.

For the best presentation and flavor, fold your roast beef slices into loose waves rather than laying them flat, and add the balsamic reduction and micro arugula just before serving to keep everything fresh and crisp.

What to Serve With Roast Beef Crostini?

Since these roast beef crostini are perfect party appetizers, they pair wonderfully with other finger foods and small bites. Try serving them alongside a cheese board with different types of hard and soft cheeses, nuts, and dried fruits to create an easy but impressive spread. A crisp white wine like Pinot Grigio or a light red like Pinot Noir would complement these crostini nicely. For a complete appetizer spread, you might want to include some marinated olives, stuffed mushrooms, or even a simple bowl of spiced nuts – these options let guests mix and match their bites while keeping everything casual and easy to eat while mingling.

Storage Instructions

Prep Ahead: You can make the horseradish cream sauce up to 2 days ahead – just keep it in an airtight container in the fridge. The baguette slices can be toasted a day in advance and stored in a zip-top bag at room temperature. This makes party prep so much easier!

Keep Fresh: Once assembled, these crostini are best enjoyed within 2 hours. If you need to wait a bit before serving, keep them covered in the fridge, but know that the bread might soften slightly. For the best texture and taste, I recommend assembling these beauties just before your guests arrive.

Components: Store any leftover roast beef and horseradish cream sauce separately in airtight containers in the fridge for up to 3 days. The toasted baguette slices will stay crispy for 1-2 days in a sealed container at room temperature. When you’re ready to serve, just assemble fresh crostini with your stored components.

Preparation Time	10-15 minutes
Cooking Time	7-8 minutes
Total Time	17-23 minutes
Level of Difficulty	Easy

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 1800-2000
• Protein: 50-60 g
• Fat: 120-130 g
• Carbohydrates: 150-160 g

Ingredients

For the crostini base:

• 1 baguette
• olive oil (a good quality extra virgin olive oil works best for flavor)

For the horseradish sauce:

• 1/2 cup sour cream
• 2 tbsp minced green onion
• salt
• 2 tbsp horseradish sauce
• black pepper
• juice of 1/2 lemon
• 1/2 cup mayonnaise (I prefer Hellmann’s mayonnaise)

For the assembly and garnish:

• balsamic reduction
• micro arugula
• flaky sea salt (I like Maldon sea salt)
• pomegranate seeds
• 1/2 lb thinly sliced roast beef (freshly sliced from the deli counter is best)

Step 1: Prepare the Baguette Slices

Start by preheating your oven to 350°F.

Cut the baguette into 1/2-inch slices, which should yield between 25 to 30 pieces.

Brush both sides of each slice with a little olive oil, then place them on a baking sheet.

Bake the slices at 350°F for 7-8 minutes, flipping them halfway through to ensure even toasting.

Once done, remove from the oven and allow to cool slightly.

Step 2: Make the Horseradish Sauce

In a medium-sized mixing bowl, combine your horseradish, sour cream, mayonnaise, minced green onion, the juice of half a lemon, and a pinch of salt and pepper.

Stir the mixture until all the ingredients are well combined and the sauce is smooth.

Step 3: Assemble the Crostini

To assemble your crostini, start by spreading a small amount of the prepared horseradish sauce on each cooled baguette slice.

Layer some roast beef on top of the sauce, followed by a dollop of the same horseradish sauce.

Add a dot or two of balsamic glaze for added flavor.

Step 4: Add Garnishes and Serve

Optional garnishes can really elevate the dish: consider adding micro arugula and a few pomegranate seeds for a pop of color and flavor.

Finish with a sprinkle of fresh cracked pepper and a pinch of flaky sea salt for added depth.

Arrange your crostini on a serving platter and enjoy this delightful appetizer!