Caramelized Onion and Gorgonzola Crostini

Name: Caramelized Onion and Gorgonzola Crostini
Prep time: 20 min
Cook time: 30 min
Total time: 50 min
Yield: 12 crostini
Ingredients: 1 baguette, sliced into 1/2 inch pieces; 2 tablespoons olive oil; Salt and pepper to taste; 2 large onions, thinly sliced; 2 tablespoons butter; 1 tablespoon balsamic vinegar; 1 cup Gorgonzola cheese, crumbled; Fresh thyme leaves for garnish

Highlighted under: Easy Home Recipes

I absolutely love whipping up these caramelized onion and Gorgonzola crostini when I'm entertaining guests or just craving something decadent. The combination of sweet, rich caramelized onions and the tangy, bold flavor of Gorgonzola cheese is simply irresistible. Topped on crispy crostini, every bite feels like a gourmet treat. Plus, the preparation is surprisingly easy, making this appetizer a go-to for any occasion. Whether it's a cozy night in or a lively gathering, these crostini never fail to impress!

Created by

Emily

Last updated on 2026-01-17T15:50:28.499Z

When I first tried caramelized onions, I was struck by their deep flavor—sweet and savory all at once. This dish started as a simple idea, but it became a staple at dinner parties thanks to its elegance and simplicity. The key is to allow the onions to cook low and slow, achieving that perfect golden-brown color without rushing the process. Patience really transforms their taste!

Pairing the onions with Gorgonzola was a no-brainer for me. The creamy, rich texture of Gorgonzola complements the sweetness of the onions beautifully, making each crostini a delightful experience. I recommend serving them warm, allowing the cheese to melt slightly for an even more indulgent treat. These crostini are sure to become a favorite!

        Why You'll Love This Recipe
        Sweet caramelized onions create a delicious flavor contrast with tangy Gorgonzola.
Easy to prepare, making it perfect for both casual gatherings and elegant soirées.
Crispy crostini provide the ideal base for these rich toppings, elevating your appetizer game.

      

Perfecting the Caramelization Process

Caramelizing onions is an essential technique that elevates the flavor profile of your crostini. Begin with medium heat to allow the onions to gradually soften without burning. Stir them frequently to ensure even cooking, aiming for a rich, golden-brown color, which usually takes about 20 minutes. If they start to stick to the pan, reduce the heat slightly and add a splash of water to deglaze, releasing those flavorful bits stuck at the bottom.

Choosing the right type of onion can greatly affect the sweetness of your caramelized topping. While yellow onions are commonly used for their balance of sweetness and acidity, sweet onions like Vidalia can create a more pronounced caramel flavor. If you prefer a sharper taste, consider using red onions, which will also add a vibrant color to your dish.

Building Flavor with Gorgonzola

Gorgonzola cheese brings a rich, creamy texture and a tangy punch that contrasts beautifully with the sweetness of the onions. Be sure to use high-quality cheese, as the flavors are pivotal to the overall taste of the crostini. If Gorgonzola is too strong for your palate, a mild blue cheese can work as a substitute, while feta offers a crumbly texture without the same pungency.

When assembling, don't skimp on the Gorgonzola; a generous amount ensures each bite has that luxurious, savory flavor. If you prefer a melted cheese topping, simply bake the assembled crostini for an extra 5 minutes until the cheese is bubbly and golden. This will create a delightful contrast with the crispy crostini and the tender onions.

Ingredients

Gather the following ingredients:

For the Crostini

1 baguette, sliced into 1/2 inch pieces
2 tablespoons olive oil
Salt and pepper to taste

For the Topping

2 large onions, thinly sliced
2 tablespoons butter
1 tablespoon balsamic vinegar
1 cup Gorgonzola cheese, crumbled
Fresh thyme leaves for garnish

Make sure all ingredients are measured out before you begin!

Instructions

Follow these steps to make your crostini:

Prepare the Crostini

Preheat your oven to 400°F (200°C). Arrange the baguette slices on a baking sheet and brush both sides with olive oil. Season with salt and pepper. Bake for 10–12 minutes, or until golden and crisp.

Caramelize the Onions

In a large skillet, melt the butter over medium heat. Add the sliced onions and sauté for about 20 minutes, stirring frequently, until they are soft and golden brown. Stir in the balsamic vinegar and cook for an additional 2 minutes.

Assemble the Crostini

Top each toasted baguette slice with a generous spoonful of the caramelized onions, then sprinkle with crumbled Gorgonzola cheese. If desired, return the crostini to the oven for an additional 5 minutes to warm the cheese.

Garnish and Serve

Remove from oven and garnish with fresh thyme leaves before serving warm. Enjoy!

Serve these delightful crostini as an appetizer or snack!

Pro Tips

When caramelizing onions, be patient and keep the heat low to avoid burning them. The longer they cook, the sweeter and more flavorful they become.

Storage and Make-Ahead Tips

If you're planning to serve these crostini at a later time, consider preparing the caramelized onions in advance. They can be stored in an airtight container in the refrigerator for up to three days. Just reheat them on low heat before assembling to retain their creamy consistency. This makes hosting a breeze, allowing you to focus on enjoying the gathering rather than juggling last-minute preparations.

For the crostini, you can pre-bake the baguette slices and store them in a sealed container at room temperature for a day. However, if you wish to keep them crisp for longer, freeze the baked slices in a single layer and store them in a zip-top bag. Reheat them in the oven at 375°F (190°C) for about 5–7 minutes before serving.

Serving Suggestions

These crostini make a fantastic appetizer, but they can also serve as a luxurious complement to a wine night. Pair them with a light red wine such as Pinot Noir or a dry white like Sauvignon Blanc to enhance the flavors of both the cheese and onions. The balance of acidity in the wine can refresh your palate between bites.

For a varied platter, consider adding additional toppings to the serving tray. Options like roasted garlic, sliced figs, or chopped walnuts can add an interesting twist and allow guests to customize their crostini experience. Each bite can then be a slightly different flavor adventure, making the appetizer even more engaging.

Questions About Recipes

→ Can I use a different cheese instead of Gorgonzola?

Yes, you can substitute with goat cheese, feta, or even mozzarella for a milder flavor.

→ How do I store leftover crostini?

Store any leftovers in an airtight container in the refrigerator for up to 2 days. Reheat in the oven for the best texture.

→ Can I make the caramelized onions ahead of time?

Absolutely! Caramelized onions can be made ahead and stored in the refrigerator for up to a week.

→ What can I serve with these crostini?

These crostini pair wonderfully with a variety of dips, olives, or a simple green salad.