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Steak and Mushroom Crostini is a delicious appetizer recipe to have on hand for any future parties and gatherings this holiday season.
So this past week has been a little different from other Christmas seasons. Usually, by now we would have the tree up all nice and decorated. However, Derek has been out of town this past week on business and we didn’t have time to get the tree up before he left.
He’s arriving home tonight, though, and I’m hoping we’ll be able to pick a tree up tomorrow. I’ve been anxious to see how Potter will react since this will be his first tree. Luna has always loved Christmas trees. She took to it right away her first Christmas. She loves napping under it and whenever she starts to feel a little frisky, she’ll play with the tree skirt.

I’m starting to get my holiday menus prepared and it had me thinking about appetizers. A good appetizer recipe is worth having this time of year, especially if you’re hosting a party. You want something that will stand out from the rest of the crowd. This Steak and Mushroom Crostini certainly does that!
I’m a bit of a mushroom fanatic. I love them with everything from pizza to even my fajitas. I really enjoy the combination of mushrooms with beef. They just go together really well, the perfect duo. This crostini really celebrates that combination with a few hints of Swiss cheese, garlic, and creamy horseradish. Sounds totally delish, right?!

This recipe is great for parties because you can do parts of it ahead of time. You can slice and toast the baguette and store it in a plastic container until you need it. You can also make the mushrooms ahead of time. Store them in the fridge and then heat them up right before you put the crostini together.
I do get a little store
Everything else can be thrown together just as your guests are arriving. They will certainly be impressed by not only the presentation but these crostini’s incredible flavor! I hope you enjoy this Steak and Mushroom Crostini as much as we do! Oh, by the way, leftover steak makes for excellent sandwiches! Yum, yum!
If you know of anyone who would love this appetizer, please share this post with all your friends and family. Just click on the social media icons below! Have a wonderful weekend and enjoy!
Steak and Mushroom Crostini
Ingredients
- 24 Slices French bread baguette
- ½ lb white button mushrooms
- ½ lb crimini mushrooms
- 1 tsp fresh thyme
- 1 Tbsp butter
- 1 Tbsp extra virgin olive oil plus more for brushing
- 2 cloves garlic
- 1½ lbs Steak Whatever cut you prefer, I used London Broil this time around.
- 2 cups Swiss cheese shredded
- 2 Tbsp prepared horseradish
- ½ cup sour cream
Steak Marinade
- 1 Tbsp Dijon mustard
- 2 Tbsp Worcestershire Sauce
- 3 Tbsp balsamic vinegar
- 1 Tbsp extra virgin olive oil
- 1 tsp salt
- 1 tsp black pepper
- 3 garlic cloves chopped
Instructions
- Place the bread slices on baking sheets. Brush each slice with the olive oil. Broil 4-6 in from the heat for 1-2 minutes or until lightly toasted.
- Make the creamy horseradish sauce by combining the horseradish with the sour cream. Refrigerate at least 1 – 2 hours for the flavors to come together.
- In a large skillet, sauté the mushrooms with fresh thyme in butter and olive oil until tender. Once the mushrooms begin to release their juices, add garlic. Cook until all liquid has absorbed.
- Remove beef from the fridge and let sit for about 30 – 60 minutes. Preheat broiler for at least 10 minutes. Broil the beef 4 in. from the heat for 7-9 minutes on each side or until meat reaches desired doneness (a thermometer should read medium-rare 135, medium 140, medium-well 145). Let stand for 5 minutes. Thinly slice across the grain.
- Evenly top the toasts with steak, mushrooms and sprinkle with Swiss cheese.
- Bake the crostini at 350 degrees for 4-6 minutes or until the cheese is melted. Top each toast with creamy horseradish. Garnish with thyme leaves.
Marinade
- Whisk together Dijon mustard, Worcestershire Sauce, balsamic vinegar, extra virgin olive oil, garlic, salt, and pepper.
- Marinade steak, if desire for at least 4 hours.
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