Olive-Stuffed Roasted Mini-Pepper Crostini with Caramelized Onions

This roasted mini pepper crostini with olives and caramelized onions is the perfect party appetizer! Make ahead, serve at room temp, easy!

Roasted Pepper Crostini with Olives
Elise Bauer

This recipe is brought to you in partnership with The California Olive Committee.

Oh my. You know a recipe hits it out of the park when a certain family octogenarian (my dad) comes over mid-party prep and can't stop eating it.

That's the problem with appetizers, right? If they're good, only half of them make it to your guests! (LOL I'm passing the blame on my father, but let's be truthful here, I'm just as guilty. Just make more. Problem solved.)

These Roasted Pepper Crostini are made with sweet mini peppers that have been halved, stuffed with salty capers, sweet cherry tomatoes, and buttery California Ripe Olives, and roasted on a bed of balsamic-tossed sliced red onions.

Roasted Pepper Crostini with Olives
Elise Bauer

When the peppers are done, you top toasted baguette slices first with the caramelized onions and then with the stuffed roasted peppers.

Every bite yields a crunchy, juicy flavor explosion! California Ripe Olives are perfect for this dish because their mild, buttery, meaty flavor balances the acidity from the tomatoes, capers, and onions. The olives are also like sponges–they absorb flavor from peppers, tomatoes, and capers during the cooking process.

Roasted Mini Pepper Crostini
Elise Bauer

Why California Ripe Olives? Forgive me for being just a little proud of my home state. The answer is quality.

Here in California there are thousands of acres of olive trees planted throughout the state–north, central, and south–that provide the olives for the ripe olive industry. Olives trees are particularly well-suited for the Mediterranean climate of California. The trees are drought resistant, can thrive in less than ideal soils, and love our long, hot summers.

In fact, California produces 95% of the olives grown in the United States.

Most of the ripe olive farms are owned and operated by families who have been farming the olives for generations. To achieve the high standards of quality needed for canned olives, the fruit must be picked by hand with care, never touching the soil. When it comes to processing the olives, every step is regulated by the USDA to ensure quality.

Back to our crostini! You can easily make the peppers and toast the bread ahead of time. You can even assemble the crostini an hour or two ahead. This appetizer works served warm or at room temperature. My one piece of advice? Make extra.

Olive-Stuffed Roasted Mini-Pepper Crostini with Caramelized Onions

Prep Time 20 mins
Cook Time 50 mins
Total Time 70 mins
Servings 24 crostini

If you want to make ahead, you can assemble the onions and peppers in the baking dish a day ahead. You can roast the peppers and toast the baguette slices a few hours ahead of serving, and assemble the crostini an hour or two before serving.

This appetizer is best served at room temperature.


  • 24 (1/4-inch thick) slices of baguette
  • 2 small red onions, peeled, thinly sliced (2 to 3 cups)
  • 3 tablespoons extra virgin olive oil
  • 1 tablespoon balsamic vinegar
  • 1/4 teaspoon salt
  • 1 cup water or stock
  • 12 mini (2- to 3-inch) red, yellow, and orange sweet peppers
  • 1 tablespoon capers, rinsed and drained
  • 12 cherry tomatoes, halved
  • 24 black or green California Ripe Olives, drained and halved
  • Several sprigs of fresh thyme


  1. Preheat the oven to 450°F:

    Set one oven rack in the upper third of the oven and another rack in the lower third.

  2. Toast the bread:

    Spread the baguette slices in a single layer on a baking sheet. Place on the top rack of the oven and toast in the oven for 4 minutes. Remove from oven and let cool to room temp.

    Elise Bauer
    Elise Bauer
  3. Line the baking dish with onions:

    Place the thinly sliced onions in a 9x13-inch baking dish and toss with 2 tablespoons of olive oil.

    Spread the onions out over the bottom of the pan. Sprinkle with 1 tablespoon balsamic vinegar and 1/4 teaspoon of salt.

    Pour 1 cup of water or stock onto the onions in the baking dish.

    Elise Bauer
    Elise Bauer
  4. Prepare the mini peppers:

    Cut the peppers in half lengthwise through the stem. Pull out and discard the seeds.

    Set pepper halves on top of the sliced onions in the baking pan, hollow side facing up.

    Elise Bauer
    Elise Bauer
  5. Stuff the peppers:

    Sprinkle 3 to 4 capers inside each pepper half. Distribute the olive halves and cherry tomato halves among the pepper cavities.

    Place a few thyme sprigs among the peppers.

    Drizzle the peppers with the remaining 1 tablespoon of olive oil.

    Elise Bauer
    Elise Bauer
  6. Roast the peppers:

    Cover the pan with aluminum foil. Bake in the oven at 450°F for about 30 minutes on the lower shelf of the oven, or until the peppers are soft.

    Remove the foil and return the peppers to the top shelf of the oven for 10 to 15 more minutes, until the peppers have started to brown at the edges.

    If the bottom of the pan becomes dry at any time, pour in a little more water. Remove the pan from the oven and remove the thyme sprigs.

    Elise Bauer
  7. Assemble the crostini:

    Move one of the peppers aside in the roasting dish to reveal the caramelized onions below. Place a forkful of onions on a toasted bread slice. Top with the pepper. Repeat until all of the crostini have been topped with peppers.

    Serve warm or at room temperature. Garnish the platter with a few sprigs of fresh thyme.

    Roasted Pepper Crostini with Olives
    Elise Bauer