Caramelized Onion Crostini is a tasty snack that’s as simple as it is fancy! Crispy bread topped with sweet, golden onions makes for a delightful bite.
These little treats are perfect for gatherings or just a cozy night in. I love making a big batch—one for me, one for the guests…oops! 😄
They’re so easy to whip up. Just roast the onions until they’re sweet and soft, and pile them on toasted bread. You’ll feel like a chef in no time!
Key Ingredients & Substitutions
Baguette: A French baguette gives a crisp texture. You can swap it for a sourdough or ciabatta for a different flavor. Just ensure whatever bread you choose is sturdy enough for the toppings!
Onions: Yellow onions are ideal for caramelization due to their sweetness. You could use red onions for a milder, slightly sharper taste, or even sweet onions like Vidalia.
Butter & Olive Oil: The mix of both adds richness. If you’re dairy-free, use all olive oil or vegan butter. For a flavor bump, try using herb-infused olive oil.
Sugar: A teaspoon of sugar helps the onions caramelize. If you prefer, you can omit it or use honey or maple syrup for a natural sweetener.
Blue Cheese: I love blue cheese for its bold flavor, but feta or goat cheese can bring a lighter texture. You can also use a vegan cheese alternative if needed.
How Do You Achieve Perfectly Caramelized Onions?
Caramelizing onions is all about patience. Here’s how to do it right:
- Start with medium-low heat; it’s essential to cook them slowly.
- Melt butter and oil together; it helps prevent burning.
- Add your sliced onions and stir well. Get them coated in that buttery goodness.
- Cook for about 30-40 minutes, stirring occasionally. If they’re browning too fast, lower the heat!
- Halfway through, sprinkle sugar to enhance sweetness and caramelization.
- Season with salt and pepper towards the end, then remove from heat.
With these tips, you’ll get beautifully sweet and flavorful onions every time! Enjoy those crostinis with your favorite drinks!
Caramelized Onion Crostini
Ingredients:
- 1 French baguette, sliced into 1/2-inch thick slices
- 3 large yellow onions, thinly sliced
- 3 tablespoons unsalted butter
- 1 tablespoon olive oil
- 1 teaspoon sugar
- Salt, to taste
- Freshly ground black pepper, to taste
- 4 oz blue cheese (or gorgonzola), crumbled
- Fresh thyme sprigs, for garnish
Time Estimate:
This delicious appetizer will take about 50 minutes to prepare. You’ll spend around 10 minutes on prep and 30-40 minutes cooking the onions until they’re perfectly caramelized. Plus, a quick 10 minutes to toast the bread—easy peasy!
Instructions:
1. Prepare the Onions:
Start by heating a large skillet over medium-low heat. Melt the butter and olive oil together in the skillet. Once it’s hot, add the sliced onions and give them a good stir so they’re coated in the buttery mixture.
2. Caramelize the Onions:
Now, let’s cook those onions slowly! You’ll want to stir them occasionally to ensure they don’t stick or burn. This will take about 30-40 minutes. Halfway through the cooking time, sprinkle the sugar over your onions to help them caramelize beautifully. Once they’re soft and golden, season with a little salt and pepper, and then take them off the heat.
3. Toast the Baguette Slices:
While the onions are cooking, preheat your oven to 375°F (190°C). Arrange the baguette slices on a baking sheet, and pop them in the oven for around 10 minutes. Flip them halfway through so they get crispy and golden on both sides.
4. Assemble the Crostini:
Now it’s time to bring everything together! Spread a layer of crumbled blue cheese on each toasted baguette slice. Then, spoon on a generous helping of your caramelized onions. Yum!
5. Garnish and Serve:
To add a fresh touch, take a small sprig of thyme and place it on top of each crostini. Serve these delicious bites warm and crisp for your guests to enjoy!
Enjoy this elegant, sweet-savory appetizer perfect for parties or as a flavorful snack!
Can I Use Different Types of Bread?
Absolutely! While a French baguette is traditional, you can use sourdough, ciabatta, or even whole wheat bread. Just make sure the bread is sturdy enough to hold the toppings.
How Do I Store Leftover Crostini?
If you have leftovers, store the assembled crostini in an airtight container in the fridge for up to 1 day. To maintain their crunch, it’s best to keep the bread and toppings separate, then toast the bread again before topping it with onions and cheese.
Can I Prepare the Onions Ahead of Time?
Yes, you can caramelize the onions a day in advance! Just store them in an airtight container in the fridge. When you’re ready to serve, simply reheat them gently in a skillet before assembling your crostini.
What Can I Substitute for Blue Cheese?
If you’re not a fan of blue cheese, you can substitute it with crumbled feta, goat cheese, or even a creamy ricotta. Each will add a unique flavor, so choose what you like best!