The French Onion Steak Sandwich with Grilled Mushrooms is a mouthwatering, hearty classic that’s perfect for anyone who dreams about steak sandwiches piled high with sweet caramelized onions, earthy mushrooms, gooey cheese, and a golden, crispy roll. This sandwich isn’t just another lunch; it’s the ultimate mashup of the best parts of a steak dinner and your favorite cheesesteak, all held together by crusty bread. It’s a crowd-pleaser that will have you and your friends savoring every cheesy, beefy bite.
Ingredients You’ll Need
Ingredients You’ll Need
When it comes to making the perfect French Onion Steak Sandwich with Grilled Mushrooms, a handful of simple, honest ingredients work magic together. Each one brings something special to the table, whether it’s deep, savory flavor, a melty finish, or irresistible crunch.
- Flank steak or ribeye (1 pound, thinly sliced): Go for ribeye if you want extra richness, or choose flank steak for a hearty, beefy bite.
- Olive oil (2 tablespoons, divided): Splitting the oil lets you caramelize onions and sear mushrooms to velvet perfection.
- Yellow onions (2 large, thinly sliced): The backbone of any French onion-inspired dish, giving sweetness and depth.
- Sugar (1 teaspoon): Just a touch helps the onions become beautifully golden and jammy.
- Salt (1/2 teaspoon): Essential for coaxing out the flavor from onions, steak, and mushrooms.
- Cremini or button mushrooms (8 ounces, sliced): Add hearty, earthy flavor and a satisfying chew.
- Garlic (2 cloves, minced): Brings fragrant warmth to the mushrooms, making each bite pop.
- Black pepper (1/4 teaspoon): Just enough to balance all those rich flavors.
- Worcestershire sauce (1 tablespoon): A little splash turns the umami dial way up for both meat and mushrooms.
- Hoagie rolls or baguette (4, split): A must for holding all your delicious fillings and soaking up the juices.
- Provolone or Swiss cheese (8 slices): Melts like a dream and adds true sandwich-shop vibes.
- Butter (2 tablespoons, softened): For toasting rolls to golden, crave-worthy crispiness.
- Fresh thyme leaves (optional): Delicate green confetti for a fresh finish and herby aroma.
How to Make French Onion Steak Sandwich with Grilled Mushrooms
Step 1: Caramelize the Onions
Start by heating 1 tablespoon of olive oil in a large skillet over medium heat. Add your thinly sliced onions, along with the sugar and salt. Let them cook slowly, stirring often, for about 20–25 minutes. The goal is deep, rich caramelization—let the onions turn soft, golden, and wonderfully sweet. Once ready, scoop them into a bowl and set aside. This step builds up the irresistible flavor base of your French Onion Steak Sandwich with Grilled Mushrooms.
Step 2: Brown the Mushrooms
Using the same skillet (no need to wash out that delicious onion residue!), pour in the remaining tablespoon of olive oil and tumble in your sliced mushrooms. Let them sear and brown for 6–7 minutes, stirring occasionally. Once they’re golden and smelling amazing, stir in the minced garlic, black pepper, and Worcestershire sauce. Let everything mingle for one irresistible minute, then scrape the mushrooms into the bowl with the onions.
Step 3: Sear the Steak
Crank up the heat to medium-high and spread your thinly sliced steak across the skillet. You want a good sizzle here! Sear the steak for 3–4 minutes, stirring occasionally, just until it’s browned outside but still tender inside. Don’t overcook—you want juicy, flavorful meat for your French Onion Steak Sandwich with Grilled Mushrooms.
Step 4: Toast the Bread
While the steak cooks, preheat your oven broiler. Slather the cut sides of your rolls or baguette pieces with softened butter and slide them under the broiler for a minute or two. Watch carefully—just until golden and crisp! This step keeps the bread from getting soggy and adds irresistible crunch.
Step 5: Assemble and Broil
Build your French Onion Steak Sandwich with Grilled Mushrooms by layering steak, caramelized onions, and mushrooms on each toasted roll. Top with two slices of provolone or Swiss cheese per sandwich. Place the sandwiches back under the broiler for just a minute or two, until the cheese has melted into gooey, bubbly bliss. Finish with fresh thyme leaves if you like, and serve piping hot!
How to Serve French Onion Steak Sandwich with Grilled Mushrooms
Garnishes
A sprinkle of fresh thyme leaves adds a little pop of color and a herby hint that perfectly echoes the dish’s French inspiration. You can also add a crack of fresh black pepper or even a few chives for some lively green notes. If you’re feeling extra, a swoosh of horseradish cream or Dijon mustard can bring a tangy twist!
Side Dishes
Classic sides take this sandwich over the top. Think crispy homemade fries, kettle chips, or a simple leafy salad with tangy vinaigrette. If you want to double down on the comfort, serve with a cup of French onion soup for dipping that gooey sandwich right into brothy goodness.
Creative Ways to Present
For a fun spin, try slicing the sandwiches into two-bite pieces and piling them on a platter for game day or gatherings. Or, serve the French Onion Steak Sandwich with Grilled Mushrooms open-faced on toasted baguette slices as a rustic appetizer. A little drizzle of balsamic glaze can also give an extra hit of sweetness and shine.
Make Ahead and Storage
Storing Leftovers
If you wind up with leftovers (which honestly, is rare), store the steak, onions, and mushrooms together in an airtight container in the fridge. Keep the rolls and cheese separate so everything stays fresh and you don’t lose that dreamy bread texture. Everything will keep well for up to 3 days.
Freezing
It’s best to freeze the steak, onions, and mushrooms without the bread or cheese. Let the mixture cool, then seal it up in a freezer-safe bag or container. It keeps its flavor and texture for up to 2 months. When you’re ready, thaw overnight in the fridge, then reheat and assemble fresh sandwiches.
Reheating
For best results, reheat your steak, onion, and mushroom mixture gently in a skillet over low heat until warmed through. If you’re in a pinch, the microwave works, but cover the bowl to keep things from drying out. Toast the bread and melt the cheese right before serving for that just-made magic.
FAQs
Can I use a different cut of steak?
Absolutely! While flank steak or ribeye are classic picks for a French Onion Steak Sandwich with Grilled Mushrooms, you can swap in skirt steak or even thinly sliced sirloin for similar juicy, tender results.
Can I make this sandwich vegetarian?
Definitely—just skip the steak and amp up the amount of mushrooms (try portobello for extra heartiness). Add some grilled bell peppers or zucchini, and you’ll still get all those French onion vibes.
What’s the best cheese for melting?
Provolone and Swiss are both winners for their mild flavor and melty stretch, but if you love a sharper bite, try fontina or even a bit of Gruyère for a nod to classic French onion soup.
Can I prep anything in advance?
Yes! The onions and mushrooms can be caramelized a day ahead and cooled in the fridge—this actually gives the flavors even more time to deepen. When you’re ready, just sear the steak, toast the bread, and assemble.
Do I have to use hoagie rolls?
Not at all! Any sturdy bread with a soft interior and crisp crust works beautifully for French Onion Steak Sandwich with Grilled Mushrooms. Baguette, ciabatta, or even thick, rustic sourdough slices are all fair game.
Final Thoughts
If you’re ready to wow your tastebuds, gather your friends, or just treat yourself to something extra-special, you absolutely have to try this French Onion Steak Sandwich with Grilled Mushrooms. With its unbeatable layers of caramelized onions, juicy steak, grilled mushrooms, and melting cheese, every bite is happiness on a hoagie roll.
Print
French Onion Steak Sandwich with Grilled Mushrooms Recipe
- Prep Time: 20 minutes
- Cook Time: 30 minutes
- Total Time: 50 minutes
- Yield: 4 sandwiches
- Category: Main Course
- Method: Stovetop, Broiling
- Cuisine: American
- Diet: Vegetarian
Description
Indulge in the savory delight of a French Onion Steak Sandwich with Grilled Mushrooms. Thinly sliced ribeye steak piled high with caramelized onions, sautéed mushrooms, and gooey cheese, all nestled in a toasted hoagie roll. This gourmet sandwich is a flavor explosion you won’t want to miss!
Ingredients
For Caramelized Onions:
- 2 large yellow onions, thinly sliced
- 1 teaspoon sugar
- 1/2 teaspoon salt
- 1 tablespoon olive oil
For Grilled Mushrooms:
- 8 ounces cremini or button mushrooms, sliced
- 2 cloves garlic, minced
- 1/4 teaspoon black pepper
- 1 tablespoon Worcestershire sauce
- 1 tablespoon olive oil
For Steak Sandwich:
- 1 pound flank steak or ribeye, thinly sliced
- 1 tablespoon olive oil
- 4 hoagie rolls or baguette sections, split
- 8 slices provolone or Swiss cheese
- 2 tablespoons butter, softened
- Fresh thyme leaves, optional, for garnish
Instructions
- Caramelize Onions: Heat 1 tablespoon olive oil in a skillet, add onions, sugar, salt. Cook for 20–25 minutes until caramelized.
- Prepare Mushrooms: In the same skillet, cook mushrooms in olive oil until browned. Add garlic, pepper, Worcestershire sauce.
- Cook Steak: Increase heat, cook steak slices until browned.
- Assemble Sandwiches: Butter and toast hoagie rolls. Layer steak, onions, mushrooms, and cheese. Broil until cheese melts.
Notes
- For richer flavor, deglaze the pan with beef broth or red wine after cooking onions.
- Alternatively, grill the steak whole and slice thinly for assembling.
Nutrition
- Serving Size: 1 sandwich
- Calories: 640
- Sugar: 8g
- Sodium: 870mg
- Fat: 32g
- Saturated Fat: 14g
- Unsaturated Fat: 16g
- Trans Fat: 0g
- Carbohydrates: 46g
- Fiber: 3g
- Protein: 42g
- Cholesterol: 110mg
