Crisp, olive oil–toasted baguette slices layered with warm, creamy brie and a glossy compote of deeply caramelized red onions, tart raspberries, balsamic vinegar, and fresh thyme. A delicate drizzle of honey balances the savory onions and bright fruit for an elegant sweet-and-savory appetizer.

Ingredients

Raspberry-Caramelized Onion Compote

• 1 Tablespoon unsalted butter
• 1 teaspoon extra-virgin olive oil
• 1 large red onion, halved and thinly sliced
• 1/4 teaspoon kosher salt, divided
• 6 ounces fresh raspberries, divided
• 2 Tablespoons granulated sugar
• 1 Tablespoon balsamic vinegar
• 1/8 teaspoon freshly ground black pepper
• 1/2 teaspoon fresh thyme leaves

Crostini

• 1 French baguette
• 2 Tablespoons extra-virgin olive oil
• 8 ounces brie cheese, chilled
• 1 to 2 Tablespoons honey
• 1 teaspoon fresh thyme leaves
• Flaky sea salt, optional

Preparation

1. Reserve the Raspberries: Set aside approximately 1/2 cup of the best-looking raspberries for finishing the crostini.
2. Begin the Onions: Melt the butter with 1 teaspoon olive oil in a wide skillet over medium-low heat.
3. Caramelize the Onions: Add the sliced onion and 1/8 teaspoon kosher salt. Cook for 35 to 40 minutes, stirring every few minutes, until the onion is very soft, greatly reduced, and deep golden brown. If the onions begin sticking before they are caramelized, add 1 teaspoon water and scrape up the browned bits.
4. Make the Compote: Add the remaining raspberries, sugar, balsamic vinegar, black pepper, remaining 1/8 teaspoon kosher salt, and 1/2 teaspoon thyme.
5. Reduce the Compote: Cook over medium-low heat for 8 to 10 minutes, stirring occasionally and gently crushing the berries. Remove the skillet from the heat when the compote is glossy and thick enough that a spoon drawn across the bottom leaves a visible trail for several seconds.
6. Cool the Compote: Let the compote cool until warm. It will continue to thicken as it rests.
7. Prepare the Baguette: Preheat the oven to 400°F. Slice the baguette diagonally into pieces approximately 1/2 inch thick.
8. Toast the Crostini: Arrange the bread on a rimmed baking sheet. Lightly brush the tops with olive oil and bake for 5 to 6 minutes. Turn the slices over and bake for another 3 to 4 minutes, until golden around the edges and crisp but not hard.
9. Add the Brie: Cut the chilled brie into thin pieces, leaving the edible rind in place. Place one piece on each crostini.
10. Warm the Brie: Return the pan to the oven for 2 to 3 minutes, just until the brie softens and begins to relax around the edges. Do not allow it to liquefy.
11. Add the Compote: Spoon approximately 2 teaspoons of warm compote over each piece of brie.
12. Finish the Crostini: Tear or lightly crush the reserved raspberries and place a small piece on each crostini. Finish with a restrained drizzle of honey, fresh thyme leaves, and a few flakes of sea salt, if desired.
13. Serve: Serve immediately while the crostini are warm and crisp.

Cook’s Notes

• Properly caramelized onions require patience. Increasing the heat will brown them more quickly but will not produce the same deep, mellow sweetness.
• Chilling the brie makes it easier to cut into neat portions.
• Placing the brie beneath the compote creates a moisture barrier that helps keep the crostini crisp.
• The compote should be thick and spoonable rather than runny. If it becomes too thick, stir in 1 or 2 teaspoons water.
• For a sweet-and-spicy variation, replace the regular honey with hot honey.
• Frozen raspberries may be used in the cooked compote. Thaw and drain them first, but use fresh raspberries for the finishing garnish.
• The compote can be refrigerated in an airtight container for up to three days. Reheat it gently before assembling the crostini.
• Assemble the crostini immediately before serving for the best texture.

Serving Suggestions

• Serve as an elegant appetizer for holiday meals, cocktail parties, or wine tastings.
• Arrange on a wood or geometric ceramic platter.
• Accompany with toasted walnuts, prosciutto, olives, or a lightly dressed arugula salad.
• Include as part of a cheese or charcuterie board.

Beverage Suggestions

• Brut sparkling wine
• Dry rosé
• Sauvignon Blanc
• Light Pinot Noir
• Sparkling raspberry-lemon water for a nonalcoholic option