Croissant Steak Sandwiches With Horseradish Mayonnaise
- 1/2 cup mayonnaise
- 1/4 cup prepared white horseradish
- 4 tablespoons butter - (1/2 stick) divided
- 3 beef tenderloin 1"-thick steaks
- 3 medium onions thinly sliced
- 8 ounces large shiitake mushrooms stemmed, and caps thinly sliced - (abt 5 cups)
- 1 cup beef broth
- 4 large croissants halved horizontally, and lightly toasted
- 2 cups arugula
Mix mayonnaise and horseradish in small bowl to blend.
Melt 1 tablespoon butter in heavy large skillet over medium-high heat. Sprinkle tenderloin steaks with salt and pepper. Add steaks to skillet and cook to desired doneness, about 5 minutes per side for medium-rare. Using tongs, transfer steaks to work surface.
Melt 3 tablespoons butter in same skillet over medium-high heat. Add onions; sauté until dark brown, about 25 minutes. Add mushrooms; sauté until tender, about 5 minutes. Add broth; boil until juices are reduced to glaze, stirring occasionally, about 1 minute. Season onion mixture to taste with salt and pepper.
Place 1 croissant bottom, cut-side up, on each of 4 plates. Spread each with horseradish mayonnaise and top with 1/2 cup arugula. Thinly slice steaks and divide among croissants. Top with onion mixture. Spread remaining mayonnaise on cut side of croissant tops. Place tops on sandwiches.
This recipe yields 4 servings.
Although this sandwich tastes great with a croissant, any bread can be used.