Caramelized Onion & Blue Cheese Crostini

So you’re having some friends over for fancy cocktails and tasty snacks. You’re looking for a good recipe that looks sophisticated, but is quick and easy to make.

Caramelizing onions takes time and patience. Do not let anyone tell you differently. When onions are caramelized to their deepest, they’re super sweet and jam-like, absolutely perfect paired with a savoury, pungent blue cheese. In this recipe, I used Stilton blue cheese because I find the slight acidity cuts the sweetness of the onions nicely. It’s a semi-hard cheese and will hold up to thin slicing. I finished the crostini with a drizzle of balsamic reduction for added punch and acidity, but that’s optional.


Something to note about the crostini: buy a fresh, crusty baguette and slice it right before you’re going to crisp it up, and cut it diagonally to create more surface area for the toppings to sit on. Slice the baguette ¾” to 1” thick and toast the slices on only one side to ensure there will be a great crunch as well as a soft interior.

Prep Time: 15 minutes
Cooking Time: 1 hour 10 min
Serving Size: 15 crostini



For the caramelized onions:
6 medium to large yellow onions, sliced ¼” thick
1 Tbsp unsalted butter
½ Tbsp olive oil
2 big pinches salt
1 tbsp dry red wine or balsamic vinegar
Fresh black pepper

For the crostini:
1 fresh baguette, cut ¾” thick on the bias
Olive oil
Maldon Salt
Fresh black pepper

75 g – 100 g Stilton blue cheese
Balsamic vinegar reduction, optional



For the caramelized onions:
1. Heat butter and olive oil in a sauté pan with lid over medium-low to low heat.
2. Add the onions to the pan and cover with lid.
3. Cook the onions for 25 minutes, covered, stirring occasionally. They will soften and slowly start to brown.
4. Remove lid, season with 2 pinches of salt and continue cooking for 30-40 minutes, stirring often until onions turn a very deep caramel colour.
5. At this point, deglaze the pan with red wine and continue to cook for an additional 1-2 minutes.
6. Turn the heat off and season with fresh black pepper.

For the crostini:
1. Pre-heat the oven broiler on high and place the oven rack in the top third of the oven
2. Place the baguette slices onto a sheet tray and drizzle generously with olive oil. Season with a good amount of Maldon or another flaky salt, and fresh black pepper.
3. Place under broiler and toast for 1 ½ – 2 minutes until just golden brown around the edges. Keep an eye on them so they do not over toast!
4. Slice blue cheese into thin pieces. You can then break up the slices into smaller pieces that will lie nicely on top of the onions.
5. Arrange the toasted baguette on a serving dish, top with 1 Tbsp caramelized onions, a piece of blue cheese and a drizzle of balsamic vinegar reduction.


100x100_Danielle-Oron Danielle is a chef, bakery owner, and food blogger who thinks she’s Korean, but is actually Israeli. Also, Danielle does not eat like a lady.