Portobello Bruschetta with Rosemary Aioli

Total Time

Prep: 1 hour 20 min. Bake: 15 min.


2 dozen

Updated: Jun. 27, 2023
By caramelizing onions, broiling peppers and whipping up a homemade aioli with fresh herbs, you will add dimensions of flavor not found in store-bought bruschetta. —Stephanie Metzger, Camp Hill, Pennsylvania
Portobello Bruschetta with Rosemary Aioli Recipe photo by Taste of Home


  • AIOLI:
  • 1/3 cup mayonnaise
  • 1 garlic clove, minced
  • 1-1/2 teaspoons lemon juice
  • 1-1/2 teaspoons balsamic vinegar
  • 1 teaspoon minced fresh rosemary
  • 1 teaspoon Dijon mustard
  • 1/4 cup packed brown sugar
  • 1/4 cup balsamic vinegar
  • 1/4 cup honey
  • 4 teaspoons minced fresh thyme or 1 teaspoon dried thyme
  • 6 large portobello mushrooms, stems and gills removed
  • 1/2 cup olive oil, divided
  • 3 medium red onions, halved and thinly sliced
  • 2 large sweet red peppers
  • 3 tablespoons thinly sliced green onions
  • 3 tablespoons minced fresh basil
  • 1 garlic clove, minced
  • 1/4 teaspoon salt
  • 1/8 teaspoon pepper
  • 24 slices French bread baguette (1/4 inch thick)
  • 1 cup fresh arugula


  1. In a small bowl, mix aioli ingredients. Refrigerate, covered, until serving.
  2. Preheat oven to 375°. In a small bowl, whisk marinade ingredients until blended. Place mushrooms in a 13x9-in. baking dish; drizzle with 1/4 cup marinade. Bake, covered, 35-40 minutes or until tender. Remove from baking dish; cool slightly. Cut into 1/2-in. strips.
  3. While mushrooms are baking, in a large skillet, heat 2 tablespoons oil over medium heat. Add red onions; cook and stir 8-10 minutes or until softened. Reduce heat to medium-low; cook 30-40 minutes or until deep golden brown, stirring occasionally. Add remaining marinade; cook 4-6 minutes or until onions are glazed, stirring occasionally.
  4. Place red peppers on a foil-lined baking sheet. Broil 4 in. from heat until skins blister, about 5 minutes. With tongs, rotate peppers a quarter turn. Broil and rotate until all sides are blistered and blackened. Immediately place peppers in a bowl; let stand, covered, 20 minutes.
  5. Peel off and discard charred skin from peppers. Remove stems and seeds. Chop peppers; return to bowl. Add green onions, basil, garlic, salt, pepper and 1 tablespoon oil. Toss to combine.
  6. Place baguette slices on ungreased baking sheets; brush with remaining oil. Bake at 375° for 4-6 minutes on each side or until golden brown.
  7. To serve, top toasts with mushrooms, arugula, onions and pepper mixture. Bake 5-8 minutes longer or until heated through. Drizzle with aioli.

Nutrition Facts

1 appetizer: 109 calories, 7g fat (1g saturated fat), 1mg cholesterol, 75mg sodium, 11g carbohydrate (7g sugars, 1g fiber), 1g protein.