Caramelized Onion and Goat Cheese Crostini
Crisp baguette slices, soft goat cheese, and golden onion ribbons make these small crostini creamy and crunchy in the same bite. Fresh thyme adds a light finish without covering the onions or cheese.
The onions need about 40–55 minutes of gentle stovetop cooking to become tender and sweet. They can be made ahead; toast the bread separately and assemble the crostini shortly before serving so the bread stays crisp and the cheese remains visibly white.
Ingredients for Caramelized Onion and Goat Cheese Crostini
- 2 large yellow onions, about 1 pound total (450g)
- 1 tablespoon unsalted butter
- 3 tablespoons olive oil, divided
- 1/2 teaspoon fine salt, or to taste
- 1/4 teaspoon black pepper, or to taste
- 1 medium baguette, about 12 ounces (340g)
- 8 ounces plain soft goat cheese (chèvre), softened enough to spread (225g)
- A few small fresh thyme sprigs, plus about 1 teaspoon thyme leaves
Yield: About 20–24 crostini, or 8–10 appetizer servings. Plan on about 15 minutes of prep and 60–75 minutes total. A narrow baguette gives you small, oval appetizer slices.
How to Make Caramelized Onion and Goat Cheese Crostini
- Slice the onions: Peel and halve them, then cut into even slices about 1/4 inch thick. Similar-sized ribbons will soften at about the same rate.
- Cook the onions: Melt the butter with 1 tablespoon olive oil in a 12-inch skillet over medium-low heat. Add the onions and salt. Cook uncovered for about 40–55 minutes, stirring occasionally at first. Start checking them regularly after about 25 minutes, and stir more often as they color. Reduce the heat to low if the edges brown before the onions soften. If the pan develops dry spots or the onions begin to stick, add water 1 tablespoon at a time. Cook until the ribbons are collapsed, tender, and golden amber, with a few darker edges and no pooled liquid. Stir in the pepper.
- Prepare the bread: As the onions near completion, preheat the oven to 400°F (205°C). Cut the baguette into 20–24 slices, about 1/2–3/4 inch thick. Lightly brush both sides with the remaining 2 tablespoons olive oil. Arrange in a single layer on one or two baking sheets.
- Toast both sides: Bake for about 7–9 minutes total, turning the slices at around 4 minutes. Watch closely near the end and remove them when they feel dry and crisp with lightly golden edges. Cool briefly before adding the cheese.
- Assemble: Spread each toast with goat cheese. Add a loose mound of onions, leaving some white cheese visible, then finish with a few thyme leaves or a small sprig. Serve soon after assembling; do not bake the topped crostini.
How Golden Should the Onions Be?
Aim for soft, noticeably reduced ribbons that range from golden amber to light brown, rather than a dark onion jam. A wide skillet gives moisture room to evaporate; a smaller, crowded pan may take longer. If the onions darken while they are still firm, lower the heat and add a tablespoon of water to loosen the pan. Let any added water cook away before topping the bread.
How to Keep the Crostini Crisp
Turning the bread as it toasts makes both sides sturdy enough for the cheese and onions. Let very hot slices cool briefly, and keep the components separate until close to serving. Moist onions will soften even well-toasted bread if the crostini are assembled hours ahead. Serve them warm or at room temperature.
Make-Ahead and Storage
Cook the onions ahead, cool them, and refrigerate them separately in a covered container. If you want a warm topping, heat them gently in a skillet before assembly. You can also cool plain toasted baguette slices completely and store them airtight at room temperature for up to two days. Keep the goat cheese separate and assemble shortly before serving; fully assembled leftovers will lose their crunch.
For another small-format goat-cheese appetizer, try sweet potato crostini with pear and walnuts.
Nutrition
Approximate nutrition per appetizer serving (about 2–3 crostini, based on 9 servings): 250 calories, 8g protein, 12g fat, and 26g carbohydrates. Approximate values per 100g of finished crostini: 285 calories, 10g protein, 14g fat, and 30g carbohydrates. Values will vary with baguette size, goat cheese, and moisture lost during cooking.
Equipment
- 12-inch skillet
- Baking sheets
- Pastry brush
Ingredients
For the onions
- 2 large yellow onions, about 1 pound total (450g)
- 1 tablespoon unsalted butter
- 1 tablespoon olive oil
- 1/2 teaspoon fine salt, or to taste
- 1/4 teaspoon black pepper, or to taste
- Water, as needed
For the crostini
- 1 medium baguette, about 12 ounces (340g)
- 2 tablespoons olive oil
- 8 ounces plain soft goat cheese (chèvre), softened enough to spread (225g)
- A few small fresh thyme sprigs, plus about 1 teaspoon thyme leaves
Instructions
- Peel and halve the onions, then cut them into even slices about 1/4 inch thick.
- Melt the butter and 1 tablespoon olive oil in a 12-inch skillet over medium-low heat. Add the onions and salt.
- Cook uncovered for 40–55 minutes, stirring occasionally at first and more often as the onions color. Lower the heat if the edges brown before the onions soften.
- If the pan becomes dry or the onions begin to stick, add water 1 tablespoon at a time. Cook until the onions are collapsed, tender, and golden amber, with no pooled liquid. Stir in the pepper.
- As the onions near completion, preheat the oven to 400°F (205°C). Slice the baguette into 20–24 pieces about 1/2–3/4 inch thick.
- Lightly brush both sides of the baguette slices with the remaining 2 tablespoons olive oil. Arrange them in a single layer on one or two baking sheets.
- Bake for 7–9 minutes total, turning the slices at around 4 minutes. Remove when dry and crisp with lightly golden edges, then cool briefly.
- Spread each toast with goat cheese. Top with a loose mound of onions, leaving some cheese visible, and finish with thyme leaves or a small sprig.
- Serve soon after assembling. Do not bake the topped crostini.
Tips
- Use a wide skillet so moisture can evaporate and the onions cook evenly.
- Lower the heat and add a tablespoon of water if the onions darken while still firm.
- Let any added water cook away before topping the bread.
- Turn the baguette slices while toasting so both sides become sturdy and crisp.
- Assemble shortly before serving to keep the bread crisp and some goat cheese visible.