This flank steak sandwich is packed with Italian-inspired flavor. Juicy grilled steak, smoky balsamic radicchio, sweet roasted red peppers, creamy mascarpone, and sturdy Italian bread come together in a sandwich that feels special but is simple enough for a weeknight dinner, summer grilling, or game day.
If you want a grilled steak sandwich that tastes bold without requiring a long marinade or complicated prep, this recipe is exactly what you need. Flank steak and skirt steak both cook quickly over high heat, making them ideal for sandwiches. A few minutes on each side is all it takes to get a tender, flavorful result when the meat is cooked to medium rare and sliced correctly.
The toppings make this sandwich stand out. Radicchio brings a pleasantly bitter edge, and grilling it with balsamic vinegar adds sweetness, acidity, and a smoky char. Jarred roasted red peppers keep the recipe easy while adding color and natural sweetness. Mascarpone cheese works like a rich Italian-style spread, softening the bolder flavors and helping everything melt together between slices of toasted bread.
This flank steak sandwich is hearty enough to serve as a main dish, but it still feels fresh and balanced. It is a great choice for casual entertaining, backyard grilling, or a fast dinner when you want something more interesting than the usual sandwich.
Ingredients for grilled flank steak sandwiches
This grilled flank steak sandwich keeps the ingredient list short and focused. Each component adds something important: richness, sweetness, bitterness, acidity, crunch, or smoky char.
- Flank steak or skirt steak: Both cuts work well for this sandwich because they are long, flat, and quick-cooking. They are also lean, so they should be cooked hot and fast and served no more than medium rare for the best texture. Overcooking can make them tough.
- Roasted red peppers: Use jarred roasted red peppers to save time. They add sweetness, color, and a soft texture that pairs beautifully with grilled steak.
- Mascarpone cheese: Mascarpone is creamy, mild, and rich. It spreads easily on toasted bread and gives the sandwich a smooth, luxurious finish.
- Radicchio: This bitter chicory has a striking deep red color and holds up well on the grill. When brushed with balsamic vinegar, it becomes smoky, tangy, and slightly sweet.
- Balsamic vinegar: Balsamic vinegar adds acidity and sweetness to the radicchio, helping balance the richness of the steak and cheese.
- Italian bread: Choose a rustic loaf that can be sliced thick enough for sandwiches. The bread should be sturdy enough to hold the steak and toppings without falling apart.
- Olive oil, kosher salt, and cracked black pepper: These simple seasonings bring out the natural flavor of the steak and vegetables.
How to make a flank steak sandwich
Step 1: Prep the vegetables
Cut the radicchio into wedges about 1 inch thick. Drizzle the wedges with olive oil and balsamic vinegar, then season with kosher salt and cracked black pepper. Let the radicchio marinate for up to one hour if you have time. This helps the balsamic flavor soak in before grilling.
Remove the roasted red peppers from the jar and slice them into strips. Set them aside so they are ready when it is time to assemble the sandwiches.
Step 2: Grill the radicchio
Preheat the grill to medium high. Place the radicchio wedges directly on the grill and cook until the edges begin to char. Turn the wedges and grill the other side. The goal is to soften the radicchio slightly while giving it smoky flavor and caramelized edges.
While the radicchio is grilling, toast the bread on both sides. Toasted bread adds texture and helps the sandwich hold up to the juicy steak and creamy mascarpone.
Step 3: Grill the flank steak
Season the steak generously with kosher salt and freshly cracked black pepper. Grill it over direct heat for about 3 to 4 minutes per side for medium rare. Because flank steak and skirt steak are lean cuts, they are best when cooked quickly over a hot grill.
PREP TIP: Once the steak is on the grill, leave it alone. Avoid poking, pressing, or constantly moving it. Letting the steak cook undisturbed helps it sear properly and keeps the juices inside.
Step 4: Assemble the sandwich
Let the steak rest before slicing. This gives the juices time to settle back into the meat. Slice the steak thinly against the grain for the most tender bite.
Spread mascarpone cheese on one side of each slice of toasted bread. Layer roasted red peppers on the bottom slice, add the sliced steak, top with grilled radicchio, and finish with the second slice of bread.
Tips for grilled flank steak sandwiches
- Make sure the grill is hot before adding the steak. A hot grill creates a better sear and helps the steak cook quickly.
- Grill flank steak for 3 to 4 minutes per side for medium rare. A medium rare temperature is about 135 degrees F.
- Do not move the steak around while it cooks. Let it sear on one side before turning it.
- Let the flank steak rest before slicing, then cut it against the grain. This is one of the most important steps for tenderness.
- If you do not enjoy radicchio, try grilled romaine instead. If roasted red peppers are not your favorite, sun dried tomatoes can bring a different sweet and tangy flavor.
- Use bread that is strong enough for steak. Very soft sandwich bread may become soggy or tear when filled.
FAQs
There are three key steps for tender flank steak. First, do not cook it past medium rare. Second, let the steak rest for at least 5 to 10 minutes after grilling so the juices can settle. Finally, slice the meat against the grain. Cutting against the grain shortens the muscle fibers, making each bite easier to chew.
Yes. You can grill the flank steak ahead of time and make the sandwiches later. Store the grilled steak in the refrigerator for up to two days. For the best texture, wait to slice the meat until you are ready to assemble the sandwiches.
What to serve with flank steak sandwiches
A flank steak sandwich is filling enough to be the main course, but a simple side dish can round out the meal. Choose something fresh, crisp, or classic to balance the richness of the steak and mascarpone.
- A chilled potato salad works well with grilled steak and toasted bread.
- A green bean salad with feta and tomatoes adds freshness without requiring much extra cooking.
- A bright slaw is always a good match for a hearty sandwich, especially if you want crunch and a little sweetness.
This steak sandwich is quick, easy and versatile!
- Flank steak cooks in about 8 minutes, making it a fast choice for dinner.
- The steak does not need to be marinated ahead of time. Season it simply and grill it hot and fast.
- You can change the toppings, bread, and spreads depending on what you have available.
- The combination of steak, balsamic radicchio, roasted red peppers, and mascarpone gives this sandwich a bold Italian-style flavor without a complicated process.
Recipe
Flank Steak Sandwich Recipe
Equipment
-
Chef’s knife
-
Cutting board
-
Meat thermometer
-
Grill
Ingredients
- 12 oz skirt steak or flank steak
- 1 head radicchio
- 1 jar roasted red peppers
- Mascarpone cheese
- 4 slices Italian bread
- Balsamic vinegar
- Olive oil
- Kosher salt to taste
- Cracked black pepper to taste
Instructions
-
Cut the radicchio into wedges about 1 inch thick. Drizzle with olive oil and balsamic vinegar, season with salt and pepper, and marinate for up to one hour.
-
Slice the roasted red peppers into strips and set aside.
-
Place the radicchio wedges on a medium-high grill and cook until charred at the edges on both sides.
-
While the radicchio grills, toast the bread on both sides on the grill.
-
Season the steak with salt and pepper. Grill for about 3 to 4 minutes per side for medium rare.
-
Let the steak rest, then slice it thinly against the grain. Spread mascarpone cheese on one side of each slice of bread. Layer roasted red peppers on the bottom slice, add sliced steak, top with grilled radicchio, and finish with the second slice of bread.
Notes
- Start with a hot grill.
- Do not cook the steak past medium rare.
- Cook 3 to 4 minutes per side to about 135 degrees F for medium rare.
- Avoid moving the steak around while it cooks.
- Let the steak rest before slicing.
- Slice thinly across the grain for the most tender texture.
Nutrition
Carbohydrates: 34g
Protein: 43g
Fat: 28g
Saturated Fat: 13g
Cholesterol: 107mg
Sodium: 2619mg
Fiber: 5g
Sugar: 13g
Nutrition information is automatically calculated as an estimate. Calorie accuracy is not guaranteed.