A little sweet, a little savory – these crostini with caramelized onions and melted cheese are the perfect comfort food appetizers.
Crostini with Balsamic Caramelized Onions, Melted Cheese & Sage Recipe
One can never have too many appetizer or hors d’oeuvres recipes. With football and hockey (I am Canadian, after all) seasons in full swing and the holidays just around the corner, I am working on filling out my appetizer recipe box, particularly with easy recipes that require few ingredients. Fewer trips to the grocery store during holiday madness makes for a much happier “me”. This recipe of caramelized onions, sage and melted cheese requires items that are found in most pantries and refrigerators. Pop into the bakery for a fresh baguette, caramelize the onions ahead of time, pour a glass of wine and you are on your way to a low-stress cocktail or Sunday football party.
I discovered the sweet and savory flavor of balsamic caramelized onions a couple of years ago. The depth of flavor comes from the sweetness of the onions mixed with the slight acidity of balsamic vinegar. I put them in everything from soup (Tortellini Soup with Balsamic Caramelized Onions & Mushrooms – seriously good) to vegetarian stews (Crockpot Chickpea Stew with Caramelized Onions) and salads (Mushroom, Caramelized Onion & Cannellini Bean Salad – one of my favorite lunches).
The recipe:
Preheat oven to 350 degrees F.
Place baguette slices on a baking sheet and brush with about 2 tablespoons olive oil. Bake until lightly toasted, about 5 minutes. Set aside.
For the onions, heat 1 tablespoon olive oil in a large skillet over medium heat. Add the onions and cook until softened, about 15 minutes.
Stir in brown sugar. Cover and cook until the onions are golden brown, about 20 minutes, stirring occasionally.
Add 1/4 cup water, cover the pan again and cook until the onions are deep golden brown, about 15 minutes.
Stir in balsamic vinegar, salt, sage and an additional 1/4 cup water. Cover the pan and cook until the liquid is absorbed. Remove from heat.
Using a vegetable peeler, shave off Pecorino Romano slices, one for each baguette slice.
Divide the caramelized onions between the baguette slices and top each one with a slice of cheese.
Place in oven and bake until cheese is beginning to melt, 3 to 4 minutes. Serve.
Other hors d’oeuvres/appetizers with caramelized onions:
Cookin’ Canuck’s (guest post on White on Rice Couple) Pancetta, Caramelized Onion Puff Pastry “Ravioli”
Cookin’ Canuck’s Brie Cheese & Caramelized Onion Whole Wheat Flatbread
Guilty Kitchen’s Caramelized Onion Dip
Brown Eyed Baker’s Onion, Mushroom & Gruyere Tartlets
Good Eats ‘n Sweet Treats’ Caramelized Onion Cranberry Cream Cheese Bites
Crostini with Caramelized Onions, Melted Cheese & Sage
Ingredients
- 1 baguette cut on diagonal into 1/2-inch slices
- 3 tablespoons olive oil divided
- 3 large yellow onions peeled and sliced thinly into semicircles
- 1 tablespoon brown sugar
- 1/2 cup water divided
- 1 tablespoon balsamic vinegar
- 1/2 teaspoon kosher salt
- 1 tablespoon minced fresh sage
- 3 ounces Pecorino Romano cheese
Instructions
- Preheat oven to 350 degrees F.
- Place baguette slices on a baking sheet and brush with about 2 tablespoons olive oil. Bake until lightly toasted, about 5 minutes. Set aside.
- For the onions, heat 1 tablespoon olive oil in a large skillet over medium heat.
- Add the onions and cook until softened, about 15 minutes.
- Stir in brown sugar. Cover and cook until the onions are golden brown, about 20 minutes, stirring occasionally.
- Add ¼ cup water, cover the pan again and cook until the onions are deep golden brown, about 15 minutes.
- Stir in balsamic vinegar, salt, sage and an additional ¼ cup water. Cover the pan and cook until the liquid is absorbed. Remove from heat.
- Using a vegetable peeler, shave off Pecorino Romano slices, one for each baguette slice.
- Divide the caramelized onions between the baguette slices and top each one with a slice of cheese.
- Place in oven and bake until cheese is beginning to melt, 3 to 4 minutes. Serve.
Nutrition
Disclosure: I am a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for me to earn fees by linking to Amazon.com and affiliated sites.
Heather (Heather's Dish) says
crostini are one of my favorite things. seriously, i could eat a bunch of them and just call it dinner! these sound amazing, especially since i’ve been craving balsamic lately 🙂
Dara (Cookin' Canuck) says
I could easily make a meal out of them too. Thanks, Heather.
a spoonful of yumm says
this looks like a perfect appetizer !
Dara (Cookin' Canuck) says
Thank you! They are always popular.
Chris @ TheKeenanCookBook says
Looks great! I could see myself easily making a meal out of this.
Dara (Cookin' Canuck) says
Chris – you’re right. They would be perfect with a salad on the side.
Rachel @ Not Rachael Ray says
Oh man. Yes please! I’m all-in with anything that has caramelized onions and melted cheese!
Dara (Cookin' Canuck) says
Rachel, you really can’t go wrong with that combination of flavors.
blog is the new black says
These.look.divine!
Dara (Cookin' Canuck) says
Thanks so much!
Katrina says
Yum! These little guys sound wonderful!
Dara (Cookin' Canuck) says
Thank you, Katrina!
Helene Dsouza says
absolutly gorgeous. Wonderful idea of flavoures. *stomachegrowl*
Dara (Cookin' Canuck) says
Thanks, Helene! My stomach is growling just thinking about them, too.
Lauren from Lauren's Latest says
I love the simplicity of this dish! It’s simple but looks so fancy!
Dara (Cookin' Canuck) says
Don’t you love recipes that make you look so good but are SO darn easy?
doodles says
carmelized onions and balsamic vinegar…………..I’m there!!
Dara (Cookin' Canuck) says
It really is an irresistible combination.
Alison @ Ingredients, Inc. says
omg i’m in heaven! Love this!
Dara (Cookin' Canuck) says
Thanks, Alison!
Bev Weidner says
This has my name written all over it. On every single crostini. My name. On them. All of them.
I’m dying.
Dara (Cookin' Canuck) says
Bev, if we ever meet in person, I promise to make a batch of these for you.
Barbara | Creative Culinary says
I love balsamic caramelized onions too. I cook a whole bag of onions overnight in the crockpot to have on hand for assorted goodies; soups, eggs and appetizers. The original recipe for crockpot cooking did not call for balsamic vinegar but it’s my standard that I add to mine when I cook them on the stovetop so of course I did. I am not kidding when I say I could simply eat a bowl of caramelized onions so of course this appetizer is just perfect for me!
Dara (Cookin' Canuck) says
That’s a great idea, Barb. Caramelized onions add a wonderful flavor to soups, salad, sandwiches, etc. and it never hurts to have extras on hand.
Sara says
Making these tonight!! Quick question- you said you can caramelize them ahead of time- do you have a tip on the best way to reheat the onions before you put the crostinis together, or do they heat up in the oven when you’re melting the cheese?
Dara (Cookin' Canuck) says
Sara, reheat the onions in a medium skillet set over low heat before transferring them to the crostini. I hope you enjoy them!
Curt says
Wow, how did I miss this awesome recipe yesterday? You’re one of my favorite blogs. I was pretty distracted yesterday and missed a few.
This is my kind of food!
Dara (Cookin' Canuck) says
Curt, thanks so much for your kind comment. Don’t feel badly – the post didn’t go up until late last night.
marla says
It is try one cannot have enough appetizer recipes. This looks great, I must start using more sage. Love that herb 🙂
marla says
PS. I am waiting on the Jelly Fish 😉
Deborah says
I’m definitely saving this recipe!! We always do all appetizers for New Year’s Eve – this would be perfect!
Katarina says
Yummy, these look really delicious!
Nettie Moore says
Can I just tell you how beautiful your blog is and how yummy your recipes are. So awe inspiring!
Choosy Beggar Tina says
I love the delicate paper thin slices of cheese. These appetizers look divine! Caramelized onions are so worth the wait.
KC Quaretti says
Dara your photo is great, it makes me want to reach right over and grab one! Will definately be trying this in the next few days!
Miss @ Miss in the Kitchen says
This looks so delicious, I really like the sage addition.
[email protected] says
How perfect that I just caramelized a batch of onions this afternoon, and happen to have sage in the fridge; a baguette will be coming home tomorrow night and making this happen.
naomi says
I’m all for making small bites a meal in themself. Love this recipe-so perfect for holiday entertaining.
Isabel says
i want to eat those NOW! they look so yummy!!!
Monet says
What a great way to start a party! This looks so good…and I’m so glad that my arm is better and I can visit and comment again! Thank you for being such an inspiration. Your words, recipes and photos…yum, yum, yum! Blessings from Austin
Tori says
This looks perfect for the next gathering I have. I love how the recipe seems very deep in flavor but very simple to make (my style!).
Nann......At Nann's Table says
Wow do these ever look delicious. I’m printing this fabulous recipe because both we would love it. You have a delightful blog. So glad I came. I am a new blogger of just 6 weeks and have so enjoyed finding other incredibly wonderful blogs like yours.
Nann