Description
This irresistible French Onion Bruschetta features deeply caramelized onions simmered in vegetable broth and fresh thyme, layered over crusty French bread, then topped with melted Swiss and mozzarella cheeses. Perfect for cozy nights in, this savory appetizer combines rich flavors and gooey cheese in a simple yet elegant bite.
Ingredients
Scale
For the Caramelized Onions
- 4 small onions, thinly sliced
- 3 tablespoons olive oil (for cooking)
- 0.5 teaspoon kosher salt
- 1 cup low-sodium vegetable broth
- 6 sprigs fresh thyme (plus more for serving)
For the Bruschetta
- 0.5 loaf crusty French bread, sliced into ½-inch thick pieces
- 4 ounces mozzarella, shredded
- 2.5 ounces Swiss or Gruyère cheese, sliced
Instructions
- Heat the skillet: Place a large nonstick skillet over medium-high heat and pour in the olive oil.
- Add onions and season: Add the thinly sliced onions to the skillet and sprinkle with kosher salt, stirring continuously to coat evenly.
- Caramelize onions: Cook the onions slowly, stirring constantly to prevent burning, for about 20 to 30 minutes until they are deeply golden brown and soft.
- Add broth: Gradually pour in the vegetable broth, stirring as the onions absorb the liquid to develop rich flavor and moist texture.
- Finish with thyme: Remove the thyme leaves from the sprigs, add them to the onions, stir to combine, then remove the skillet from the heat.
- Prepare for broiling: Preheat your oven’s broiler and line a baking sheet with parchment paper.
- Arrange bread slices: Place the ½-inch thick slices of crusty French bread on the baking sheet evenly spaced.
- Top bread with onions: Spoon generous amounts of the caramelized onion mixture over each bread slice.
- Add cheese layers: Place a slice of Swiss or Gruyère cheese on top of the onions, then sprinkle shredded mozzarella over each piece.
- Broil: Place the baking sheet under the broiler for 4 to 6 minutes, watching carefully until the cheese melts fully, bubbles, and turns golden brown.
- Cool and garnish: Remove from oven, let the bruschetta cool for 5 to 10 minutes, then garnish with additional fresh thyme leaves before serving.
Notes
- Caramelizing onions slowly is key to developing rich flavor and sweetness—do not rush this step.
- Watch the bread closely when broiling to avoid burning the cheese.
- Use fresh thyme for best flavor, but dried thyme can substitute if necessary (use about 1 teaspoon).
- Low-sodium vegetable broth helps control salt levels but you can adjust salt to taste.
- Any sturdy crusty bread can be used if French bread is unavailable.
