Steak Sandwich Platter with grilled onions, mushrooms, blue cheese, and Steakhouse Aioli

  • Author: Tonja Engen



  • 3 tablespoons spicy brown mustard
  • 1/4 cup honey
  • 1 garlic clove, minced
  • 1/2 cup mayonnaise
  • kosher salt and pepper
  • 1 lb beef tenderloin
  • 1 8-oz package mushrooms
  • 1 yellow onion sliced 1/4 inch thick
  • 1 cup of arugula
  • 1/2 cup blue cheese
  • 1 package ciabatta buns
  • 3 tablespoons extra virgin olive oil


  1. In a small bowl or food processor, add the mustard, honey, garlic and mayonnaise processing until smooth. Season with salt and pepper to taste. Refrigerate until ready to use.
  2. Coat the tenderloin in 1 tablespoon olive oil and cover liberally with salt and pepper. On a prepared grill, cook the beef over med-high heat, turning occasionally to create a crust. Continue to grill until medium rare, approximately 20 minutes. (use a grill thermometer to determine temperature, I remove around 125 degrees.) Transfer to a plate and allow to rest for 10 minutes covered with foil.
  3. In a large skillet over medium-high heat, add the onions and mushrooms with olive oil and season with salt and pepper. Saute’ the onions and mushrooms until they start to char, approximately 15 minutes. Transfer to a plate.
  4. Brush both sides of the ciabatta bun with olive oil and grill, cut side down, until lightly charred, approximately 5 minutes.
  5. To Arrange: Slice the beef into 1/2 inch slices, and arrange on platter. Add rest of sandwich ingredients arranging onion/mushroom mixture, blue cheese and aioli in separate bowls.
  6. To assemble: Brush both cut sides of the bread with aioli, top the bottom half with grilled onion/mushroom mixture and then layer the beef on the mixture. Top the beef with blue cheese, arugula and then the top of the ciabatta. Serve and enjoy.