The most flavorful sandwich ever created and all made on your grill. Buttery beef tenderloin layered with grilled onions and mushrooms, blue cheese, spinach and a spicy steakhouse aioli piled high on a grilled ciabatta roll! Does it get any better? Oh….it does….read on to find out how much better!

Grilled Beef Tenderloin Sandwich with Spicy Steakhouse Aioli | The Suburban Soapbox


I dreamed of this sandwich. Literally, I had a dream one night and this sandwich was in it. It was so real that I could taste it. The creamy blue cheese and the buttery beef mixing with a mystery aioli, every bite was bursting with deliciousness. The aioli was spicy, garlicky and smooth….something I never had before. It was even better than my Short Rib and Taleggio Grilled Cheese Sandwich….which is near impossible. I had to recreate it, I had to make it real.

A few days later, I received a package at the door…..El Diablo Mustard. Spicy, savory mustard delivered to my home to try in any recipe I wanted. I made a pizza….I made a steak sauce….and I made a Spicy Steakhouse Aioli. To go on the dream sandwich. A match made in….my dreams. 🙂


Get the Recipe: Grilled Beef Tenderloin Sandwich with Spicy Steakhouse Aioli

lunch time calls for this grilled beef tenderloin sandwich!
No ratings yet


  • 3 tablespoons El Diablo Spicy Steakhouse Mustard
  • 1/4 cup honey
  • 1 garlic clove
  • 1/2 cup mayonnaise
  • kosher salt and pepper
  • 1 lb beef tenderloin
  • 5 large mushrooms, cleaned
  • 1 large vidalia onion sliced 1/2 inch thick
  • 1 cup baby spinach
  • 1/4 cup blue cheese
  • 1 ciabatta loaf, split lengthwise
  • 3 tablespoons extra virgin olive oil


  • In a mini food processor, add the mustard, honey, garlic and mayonnaise processing until smooth. Season with salt and pepper to taste. Let sit for 30 minutes.
  • 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.
  • Drizzle the onions and mushrooms with olive oil and season with salt and pepper. Grill the onions and mushrooms until soft, approximately 5-7 minutes. Transfer to a plate.
  • Brush both cut sides of the ciabatta with olive oil and grill, cut side down, until lightly charred, approximately 5 minutes.
  • To assemble: Slice the beef into 1/2 inch slices, set aside. Brush both cut sides of the bread with aioli, top the bottom half with grilled onions and then layer the beef on the onions. Top the beef with the mushrooms, blue cheese, spinach and then the top of the ciabatta. Cut into four sandwiches, serve immediately.
Serving: 1g, Calories: 972kcal, Carbohydrates: 75g, Protein: 34g, Fat: 60g, Saturated Fat: 16g, Cholesterol: 97mg, Sodium: 1039mg, Potassium: 554mg, Fiber: 2g, Sugar: 19g, Vitamin A: 785IU, Vitamin C: 4.9mg, Calcium: 73mg, Iron: 3.4mg