Caramelized Onion and Roast Beef Au Jus Crostini

This sophisticated crostini transforms the classic French Dip sandwich into an elegant appetizer. Thinly sliced, tender roast beef is layered over a creamy Gruyère spread and sweet caramelized onions, all finished with a concentrated, savory au jus reduction. The combination delivers a rich, umami-packed bite with a delightful crunch from the toasted bread.

Meat & Poultry

Ingredients

1 baguette, thinly sliced and toasted
2 tablespoons olive oil
2 large yellow onions, thinly sliced
1 tablespoon balsamic vinegar
8 ounces thinly sliced roast beef
1/2 cup beef au jus, warmed
4 ounces Gruyère cheese, shredded
Fresh thyme for garnish
Salt and freshly ground black pepper to taste

Method

In a large skillet, heat olive oil over medium-low heat. Add sliced onions and cook slowly, stirring occasionally, for 25-30 minutes minutes until deeply caramelized and golden brown. Stir in balsamic vinegar during the last 5 minutes of cooking. Season with salt and pepper.
Preheat oven to 375°F (190°C). Arrange baguette slices on a baking sheet.
Top each baguette slice with a spoonful of caramelized onions.
Place a small amount of thinly sliced roast beef on top of the onions.
Sprinkle shredded Gruyère cheese over the roast beef.
Bake for 5-7 minutes minutes, or until the cheese is melted and bubbly.
Drizzle each crostini with a small amount of warm beef au jus.
Garnish with fresh thyme leaves and serve immediately.

Chef's Tip & Pairing

For the best flavor, use a high-quality, rare roast beef, which will remain tender when served. This crostini pairs beautifully with a medium-bodied, savory red wine like a Cabernet Franc or a classic Bordeaux.

From the Tini Crostini Collection