London Broil and Portobello Sandwich Recipe

Name: London Broil and Portobello Sandwich
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Yield: 4 servings
Ingredients: 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

Servings: persons

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.

2024

kcal

Calories

223

Fat

Carbs

Protein

Fat Carbs Protein

* Per serving · 4 servings · Values may vary.

Tips for the best results

Read through all the steps once before you start and measure out your ingredients first — it makes everything go more smoothly.
Taste as you go and adjust the seasoning before serving.
Avoid overcrowding the pan — cook in batches if needed for the best texture.
Let the dish rest for a few minutes before serving so the flavors settle.
Store leftovers in an airtight container in the fridge and enjoy within a few days.

Variations & substitutions

Feel free to swap in similar ingredients you already have on hand and adjust seasoning to taste.

No specific allergen information. Please check the ingredient list for possible allergens.

My Personal Notes

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How did you like this recipe?

This recipe makes 4 servings. You can adjust the portion size directly on this page.

You need 13 ingredients. The key ingredients include: 1 1/2 pound London broil, 1/2 cup olive oil, plus more for brushing steak, Salt and pepper, 1/4 cup balsamic vinegar, and more.

Yes, London Broil and Portobello Sandwich falls under the General category and is a great choice for this type of meal.

Store leftovers in an airtight container in the refrigerator for up to 3–4 days. Reheat gently before serving.

That's it — enjoy your meal!

London Broil and Portobello Sandwich

Tips for the best results

Variations & substitutions

My Personal Notes

How did you like this recipe?

Frequently Asked Questions