Caramelized Onion and Gorgonzola Crostini

Name: Caramelized Onion and Gorgonzola Crostini
Prep time: 10 min
Cook time: 20 min
Total time: 30 min
Yield: 4 servings
Ingredients: 1 large onion, thinly sliced; 2 tablespoons olive oil; 1/2 teaspoon salt; 1/2 teaspoon black pepper; 1/4 cup Gorgonzola cheese, crumbled; 1 French baguette, sliced into thin rounds; 1 tablespoon fresh thyme, chopped (optional)

Highlighted under: World Table

I absolutely love making these Caramelized Onion and Gorgonzola Crostini as a simple yet elegant appetizer. The rich, sweet flavor of the caramelized onions perfectly complements the tangy, creamy Gorgonzola cheese. Every time I serve them, they're a guaranteed hit at parties or gatherings. The blend of textures from the crispy crostini and the soft toppings creates a delightful bite that’s hard to resist. Plus, they come together quickly in about 30 minutes, which is always a bonus when entertaining guests!

Created by

Anna

Last updated on 2026-01-17T15:44:28.305Z

When I first created this recipe, I wanted something that was both delicious and visually impressive. After experimenting with ratios, I found that a longer caramelization process truly enhances the sweetness and flavor of the onions. I learned that cooking them slowly allows their natural sugars to develop, making them deeply caramelized.

Another tip is to use a good-quality Gorgonzola cheese as it brings the perfect amount of creaminess and sharpness that balances the sweetness of the onions. Pairing them on a crunchy crostini just elevates everything!

        Why You Will Love This Recipe
        Sweet and savory combination that tantalizes the taste buds
Easy to prepare and perfect for gatherings
Versatile topping that can be enjoyed warm or at room temperature

      

The Art of Caramelizing Onions

Caramelizing onions is a transformative process that brings out their natural sweetness. Ensure you use a large skillet to give the onions ample space to cook evenly. Stir them occasionally over medium heat to avoid burning, which can happen surprisingly quickly. It should take about 20 minutes for the onions to turn a rich, golden brown—watch for them to become glossy and soft. This patience pays off, as they develop a depth of flavor that will elevate your crostini.

If you prefer a deeper flavor profile, consider adding a splash of balsamic vinegar or a pinch of sugar during the caramelization process. This can enhance the sweetness of the onions while introducing a slightly tangy note that balances beautifully with the Gorgonzola cheese. Just a teaspoon of sugar can make a significant difference, but be careful not to overdo it, as too much sugar can make the onions cloying.

For those looking to advance their skills, explore the addition of complementary aromatics while caramelizing. A bay leaf or a sprig of rosemary can infuse the onions with a lovely herbaceous note. Just remember to remove these before assembling your crostini, as they can be tough and are not meant to be eaten!

Perfecting Your Crostini

The crostini serves as the perfect base for the rich toppings. Use a French baguette for its crusty texture and slight chew; this will stand up to the toppings without becoming soggy. When slicing the baguette, aim for rounds that are about 1/2 inch thick. This thickness ensures a satisfying crunch while allowing enough surface area for the caramelized onions and cheese.

Baking the baguette slices at 375°F for 5-7 minutes strikes the right balance between crisping and browning. Keep a close eye on them; you want a light golden color. Too long in the oven can lead to overly hard crostinis. I recommend baking them until just before they reach your desired crispness, as they will continue to harden slightly as they cool.

For a touch of variety, consider experimenting with different types of bread. A ciabatta or sourdough also works well, lending their unique flavors and textures. Likewise, you can infuse your olive oil with garlic or herbs before brushing—just heat the oil gently and add minced garlic until fragrant to create an aromatic layer in your crostini.

Ingredients

Gather the following ingredients to create these delectable crostinis:

Ingredients

1 large onion, thinly sliced
2 tablespoons olive oil
1/2 teaspoon salt
1/2 teaspoon black pepper
1/4 cup Gorgonzola cheese, crumbled
1 French baguette, sliced into thin rounds
1 tablespoon fresh thyme, chopped (optional)

Make sure to have all your ingredients ready for assembly!

Instructions

Follow these simple steps to create your delicious crostinis:

Caramelize the Onions

In a large skillet, heat olive oil over medium heat. Add the sliced onions and sprinkle with salt and pepper. Cook slowly for about 20 minutes, stirring occasionally until the onions are golden brown and sweetened.

Prepare the Crostini

While the onions are caramelizing, preheat your oven to 375°F (190°C). Arrange the baguette slices on a baking sheet and brush lightly with olive oil. Bake for about 5-7 minutes until they are crispy and golden.

Assemble the Crostinis

Once the crostini is ready, top each piece with a spoonful of the caramelized onions and sprinkle with Gorgonzola cheese. If using, add fresh thyme on top for an extra burst of flavor.

Enjoy these crostinis warm as a delightful appetizer.

Pro Tips

For an added touch, drizzle balsamic reduction over the completed crostini just before serving.

Serving Suggestions

These Caramelized Onion and Gorgonzola Crostini are versatile and can be served as part of a larger cheese and charcuterie board. Pair them with fresh fruits like figs or grapes to enhance the sweet and savory experience. You could also provide a drizzle of honey on the side to allow guests to personalize their bites with a touch of sweetness.

If you're preparing these crostini for a gathering, considering making a larger batch is a good idea, as they tend to disappear quickly! An easy way to avoid any last-minute chaos is to prep the caramelized onions and bake the crostini ahead of time, only assembling them just before serving to maintain their texture.

If you're looking for a fun twist, serve the crostini with a side of balsamic reduction for drizzling. This adds an extra layer of flavor that complements both the onions and Gorgonzola beautifully, creating a sophisticated touch that’s sure to impress your guests.

Storage and Reheating

If you have leftovers, store the caramelized onions and crostini in separate airtight containers. The onions can last up to a week in the fridge, while the crostini are best consumed within 2-3 days as they tend to lose their crispness. To revive the crostini, reheat in a 375°F (190°C) oven for about 5 minutes to regain their crunch.

For those looking to meal prep, you can also freeze the caramelized onions. Allow them to cool completely, then portion them into a freezer-safe bag. When ready to use, thaw them in the refrigerator overnight and reheat on the stovetop over low heat until warmed through. This method preserves their rich flavor perfectly for future gatherings or last-minute snack cravings.

Avoid assembling the crostini until just before serving to prevent the toppings from making the bread soggy. If preparing for a party, you might even consider offering the toppings in a small dish so guests can create their own crostini, making it interactive and reducing the risk of your hard work getting soggy before the first bite!

Questions About Recipes

→ Can I make the caramelized onions in advance?

Yes, you can caramelize the onions a day ahead and store them in the refrigerator. Just reheat before assembling the crostinis.

→ What type of bread can I use instead of baguette?

You can use any crusty bread, such as ciabatta or sourdough, as an alternative to baguette.

→ Is it possible to use another cheese?

Absolutely! While Gorgonzola adds a unique flavor, Brie or goat cheese would also work beautifully.

→ How long do these crostinis stay fresh?

They are best eaten fresh but can be stored in an airtight container in the fridge for up to 2 days.