Because these caramelized onions for the bruschetta is so deeply flavored, any style of extra-virgin olive oil is suitable for this recipe. Be patient while cooking the onions. Long, slow cooking renders them sweet with a lasting flavor. You can prepare them ahead, if you wish. And do use your best balsamic vinegar. The intensity of balsamic vinegar varies; add it drop by drop until it imparts a complexity to the onions, but not enough so they taste of vinegar.–Fran Gage
Caramelized Onion-Balsamic Vinegar Bruschetta
- 6 tablespoons extra-virgin olive oil divided
- 2 large onions (about 2 pounds), peeled, halved, and thinly sliced
- Fine sea salt
- Balsamic vinegar to taste
- 4 slices grilled or toasted bread
- Fleur de sel and freshly ground black pepper
- Heat 4 tablespoons of the oil in a large skillet over high heat until it trembles, becomes aromatic, and easily coats the bottom of the pan. Add the onions and turn the heat to very low. Sprinkle with salt. Cook the onions uncovered, stirring occasionally, until they are the color of a polished mahogany table, about 1 hour. They will shrink dramatically.
- Transfer the onions to a bowl and let them cool. Add balsamic vinegar drop by drop until the flavor of the onions is complex but not vinegary. Sprinkle with fleur de sel if needed.
- To make the bruschetta, brush the bread with the remaining 2 tablespoons oil.
- Put a generous pile of onions on each slice of bruschetta. Add a few grindings of pepper, and serve immediately.
Editor’s NoteThe bruschetta shown in the foreground is a Mustard Greens Bruschetta. The bruschette at the top and to the right are topped with caramelized onions and balsamic vinegar.
Recipe Testers’ Reviews
The result of the beautiful mahogany-colored caramelized onions was creamy, savory and superb in taste. The addition of a few drops of balsamic vinegar provided the crowning essence of flavor at the end.
This caramelized onion and balsamic vinegar bruschetta hors d’oeuvre was fantastic. This recipe was a lot easier than the caramelized onion recipes I’ve used in the past. I made this twice, the second time I crumbled gorgonzola cheese on top, and four servings weren’t enough. I’ll definitely use this recipe again for upcoming holiday get togethers.
Such a simple approach to an hors d’oeuvre hardly needs a recipe, but the result was delicious. Use enough vinegar to taste, though not so much as to overwhelm the caramelized onions. Equally good when made with regular onions or sweet (Vidalia-type) onions. Smaller bruschetta slices are appropriate for appetizers. A good recipe to have in your repertoire, as the ingredients are usually available.
This is a very simple recipe. The only thing they left out was the patience. The soft flavorful caramelized onions with the crunch and crispness of the bruschetta make it all worth it. Next time I’ll use a larger pan and double the batch. I used some super-fresh white onions. It was great.
Delicious! Both my guests and I loved it. I also made it again to serve over steaks. This will become a staple in my home not only to serve as bruschetta but to serve over steaks and roast chicken. This is the fast way to have something similar to a pissaladiere Niçoise for dinner.
Although this delicious sweet-tart caramelized onion jam on bruschetta is simple to make with easy-to-find ingredients, it provides the cook the opportunity to break out her best oil, balsamic and specialty salts. As with all eats simple and straightforward, the quality of each ingredient shines through. As the onions cooks long and slow, flavors emerge that are rich and deeply satisfying. I made this on a breezy August day when just a hint of fall was in the air. It made me look forward to the months to come when dishes like this will be welcome.
The result of this bruschetta recipe are a wonderfully coloured, aromatic and densely flavoured compote-style combination. It’s fairly rich and sweet, so other than toasted bread, it could be paired well with something of a more savoury nature. Perhaps even nestled over a wheel of brie and baked for a rich, gooey, dip-able appetizer.
After caramelizing the onions, this was a fast and delicious bruschetta! The instructions were straightforward, but I couldn’t achieve the “polished mahogany table” color on the caramelized onions. I’ll definitely make the recipe again, though, but I may add a little goat cheese next time.
Mmmmm…Caramelized onions. A great use of my very best balsamic. Love the texture of the almost jam-like sticky onions on the crispy bruschetta.
As simple as this recipe may seem, the flavor of this bruschetta was very complex. The caramelized onion became sweet as it was cooked for a long time, which complimented the deep and tangy flavor of the balsamic vinegar. Having good quality ingredients is essential for this hors d’oeuvre.
Don’t give up on the onions if they take longer to caramelize than the recipe states—they’re worth the wait! The flavor of the caramelized onions is balanced beautifully by the balsamic vinegar. It’s unbelievably rich and tasty when served on the bruschetta that has been brushed with olive oil.
So simple yet divine. The slow caramelization of the onions, the aged balsamic vinegar, and the fleur de sel makes this dish definitely Testers Choice worthy.
If you’re looking for an hors d’oeuvre to pass around at your next party, try this recipe for Caramelized Onion and Balsamic Vinegar Bruschetta. I just love how the natural sweetness of the onions is cajoled out of hibernation when patiently cooked. The time required to achieve the onion’s amber color results in a remarkably pleasing topping on a slice of toasted baguette. Each bite fills your mouth with a balance of sweet and tart flavors. It’s something definitely to reach for when that tray comes your way.
Originally published September 08, 2009