London Broil and Portobello Sandwich

• 1 1/2 pound London broil
• 1/2 cup olive oil, plus more for brushing steak
• Salt and pepper
• 1/4 cup balsamic vinegar
• 4 portobello mushroom caps, cut in slices
• 1 Vidalia onion, cut in rings
• 1/2 cup mayonnaise
• 1 tablespoon grated horseradish or grainy mustard
• 1/2 cup chopped fresh parsley
• 1/2 lemon, juiced
• 4 pieces ciabatta bread, split horizontally
• 1/4 pound Fontina, sliced
• 1/3 cup (packed) coarsely chopped arugula leaves

1. Preheat oven broiler for 5 minutes.
2. Brush both sides of London broil with olive oil and season with salt and pepper.
3. Place the steak on a broiler pan and broil about 4-inches from the heat source, about 5 minutes per side.
4. Lay the portobellos and onions in a single layer on a sheet pan lined with aluminum foil.
5. Drizzle with oil and vinegar then put in the oven and roast for 10 minutes.
6. Remove the steak to a cutting board.
7. Let rest for 5 minutes then slice the steak thinly against the grain.
8. In a small bowl, combine mayonnaise, horseradish, parsley, and lemon juice.
9. Spread mayonnaise mixture on both sides of the split ciabatta.
10. Lay several slices of steak on the bread and mound with a bit of mushrooms and onions.
11. Cover with a couple of slices of cheese.
12. Garnish with arugula, and serve.

broil, olive oil, salt, balsamic vinegar, portobello mushroom caps, vidalia onion, mayonnaise, horseradish, parsley, lemon, bread, arugula

Taken from www.foodnetwork.com/recipes/tyler-florence/london-broil-and-portobello-sandwich-recipe.html (may not work)