Grilled Steak and Portobello Stacks - Grillsanity!

March Madness is brewing with anticipation and fervor as we get ready for the biggest three weeks of tournament excitement of the year. Such mayhem requires fuel and worthy sustenance, and Grillsanity is here to keep the grill blazing and the gameday spread bountiful through all 67 grudge matches.  We start this season with Grilled Steak and Portobello Stacks, featuring layers of marinated steak, tender mushrooms, balsamic onions, horseradish sauce, vegetables, and toasted bread.  Each bite offers eruptions of flavor to match the back and forth action of the games to keep you fed and energized.

Each component of this sandwich gets a unique preparation to build a layering of flavors and textures that is amazing.  The steak is rubbed with olive oil and herbes de Provence, and then refrigerated for at least two hours to marinate and tenderize. Likewise, the mushrooms are tossed in balsamic vinegar and olive oil. The balsamic onion mixture is a reduction of onion, sugar, salt, pepper, oil, and balsamic vinegar for a sweet and succulent savor. The spicy horseradish sauce is a creamy mixture of sour cream, Worcestershire sauce, and prepared horseradish. Grilled to perfection and layered on butter-toasted bread with fresh salad greens, red wine vinaigrette, and roasted sweet red peppers, these stacked sandwiches are sure to bring a smile even if your team is down.

Serves 6-8

Grilled Steak and Portobello Stacks Ingredients

  • 2 tablespoons plus 1/4 cup olive oil, divided
  • 1 tablespoon herbes de Provence
  • 1 beef tenderloin roast (1-1/4 pounds)
  • 4 large portobello mushrooms
  • 2 tablespoons balsamic vinegar

Balsamic Onion

  • 1 large onion, halved and thinly sliced
  • 4-1/2 teaspoons sugar
  • 1/2 teaspoon salt
  • 1/2 teaspoon pepper
  • 1 tablespoon olive oil
  • 2 tablespoons balsamic vinegar

Horseradish Sauce

  • 1/2 cup sour cream
  • 1-1/2 teaspoons prepared horseradish
  • 1/4 teaspoon Worcestershire sauce


  • 12 slices white bread
  • 1/4 cup butter, melted
  • 4 cups spring mix salad greens
  • 2 tablespoons red wine vinaigrette
  • 3/4 cup julienned roasted sweet red peppers

Grilled Steak and Portobello Stacks Directions

  1. In a small bowl, combine 2 tablespoons oil and herbes de Provence. Rub over tenderloin; cover and refrigerate for 2 hours. Place mushrooms in a small bowl; toss with vinegar and remaining oil. Cover and refrigerate until grilling.
  2. In a large skillet, cook the onion, sugar, salt, and pepper in oil over medium heat for 15-20 minutes or until golden brown, stirring frequently. Remove from the heat; stir in vinegar. Set aside.
  3. In a small bowl, combine the sauce ingredients. Cover and refrigerate until serving.
  4. Grill tenderloin and mushrooms, covered, over medium heat for 8-10 minutes on each side or until meat reaches desired doneness (for medium-rare, a thermometer should read 135°; medium, 140°; medium-well, 145°) and mushrooms are tender. Let tenderloin stand for 10 minutes.
  5. Meanwhile, brush both sides of bread with butter. Grill over medium heat for 1 minute on each side or until browned. Toss salad greens with vinaigrette. Cut tenderloin and mushrooms into thin slices.
  6. Divide mushrooms among four slices of bread. Layer with roasted peppers, greens and another slice of bread. Top each with onion mixture and beef. Spread sauce over remaining slices of bread; place over beef. Cut each sandwich diagonally in half.

Taken from