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Caramelized Onion Crostini

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  • Author:
  • Prep Time: 15 mins
  • Cook Time: 1 hour
  • Total Time: 1 hour 15 minutes
  • Yield: 20-22 pieces 1x
  • Category: Appetizer
  • Method: n/a
  • Cuisine: American
  • Diet: Vegan


Balsamic caramelized onion crostini with creamy cashew ricotta cheese. The perfect vegan holiday appetizer.



For the Cashew Ricotta (see note below for substitutions)

  • 1 cup raw cashews
  • 1 tablespoon fresh lemon juice
  • 2 teaspoons white miso
  • 1 small garlic clove
  • 1/4 teaspoon fine sea salt

For the Crostini

  • About 3 tablespoons extra virgin olive oil, divided
  • 67 small yellow onions (about 1 3/4 pounds), thinly sliced
  • 1 teaspoon dried thyme (or 2 teaspoons fresh)
  • 1/4 teaspoon fine sea salt
  • 1/4 teaspoon freshly ground black pepper
  • 1 tablespoon balsamic vinegar
  • 1 baguette, cut into 1/2-inch-thick rounds


  1. Start the cashew ricotta. Place the cashews in a bowl and cover with boiling water. Soak for at least 30 minutes.
  2. Preheat the oven to 375ºF.
  3. Meanwhile, start the onions. Heat 2 tablespoons oil in a large non-stick skillet over medium heat. Add the onions, thyme, salt, and pepper, and toss to coat. Cover tightly with a lid and cook until the onions have released some of their liquid, about 5 minutes.
  4. Uncover, reduce the heat to very low, and cook until the onions are brown, pasty, and mostly broken down, about 1 hour. If the onions start to look too dry, add a tablespoon or 2 of water to the pan; if they’re starting to crisp, reduce the heat. When the onions are done, stir in the vinegar, and cook for 1 minute more. Turn the heat off and set aside.
  5. Meanwhile, place the baguette slices on a baking sheet in a single layer and lightly drizzle with olive oil oil. Bake until lightly golden, 8 to 10 minutes.
  6. Finish the ricotta. Drain the cashews and place in a food processor or Vitamix. Add the lemon juice, miso, garlic, and salt. Pulse until everything is broken down. Add 1/4 cup water and continue pureeing until the mixture is creamy. Taste and adjust the seasonings, if needed. 
  7. To assemble, spread about 2 teaspoons ricotta on each toast and top with a heap of onions. Serve immediately.


If you don’t feel like making this “ricotta”, use a store-bought vegan cheese spread instead. If you eat dairy, feel free to sub with goat cheese or Boursin.


  • Serving Size: 1 piece
  • Calories: 99
Tofu with tomatoes.

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