This flank steak sandwich is full of Italian flavors! Sweet bell peppers balance the bitter tanginess of radicchio roasted with balsamic vinegar. This is an easy summer grilling recipe or an unexpected twist on tailgating recipes.
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This is the ultimate flank steak sandwich for summer grilling, tailgating or game day! Cooking steak at home is easier than you think, and it's FAST!
We're using flank steak or skirt steak here, which are cuts that you must cook "high and fast" which means a very hot grill for just a few minutes on each side and no further than medium-rare.
And let's zhuzh it up with classic Italian flavors. Grilling bitter radicchio slathered in balsamic vinegar provides another layer of smokiness, and store-bought roasted red peppers keep us on track for this quick and easy vibe.
It all adds up to a tasty flank steak sandwich made for discerning grownups, with very little effort. For more sandwich recipes try my eggplant sandwiches or these salami sandwiches with frico and mostarda.
Ingredients for grilled flank steak sandwiches
We are all about grilling when it comes to this flank steak sandwich recipe. We'll grill the steak, as well as some marinated radicchio for bittersweet smoky flavor.
- Flank steak or skirt steak: Both of these cuts are great for grilling and sandwiches. They are both long, flat cuts that are pretty lean. Because there is so little fat and they are from tougher muscles, you'll need to cook them quickly at high heat and not go past medium-rare to ensure tenderness. If you overcook these cuts, they will be tough and hard to chew.
- Roasted red peppers: Keep things simple and use these straight from the jar! Yay for store-bought shortcuts.
- Mascarpone cheese: Sometimes called Italian cream cheese, mascarpone cheese is not quite as thick and not quite as tangy as the American version.
- Radicchio: I love this bitter chicory and its beautiful color. It stands up well to grilling and can take on the flavors of the balsamic.
- Balsamic vinegar: This will add a great acidity and sweetness to the radicchio.
- Italian bread: If you can find a rustic Italian loaf that would be great. Otherwise, maybe a French country bread. Just make sure you can get sandwich slices from it, and that it's sturdy enough to stand up to steak.
How to make a flank steak sandwich
Step 1: Prep the vegetables
Cut radicchio into wedges about 1 inch thick, drizzle with a bit of olive oil and balsamic vinegar, season with salt and pepper, and marinate for up to one hour.
Slice roasted red peppers into strips.
Step 2: Grill the radicchio
Preheat a grill to medium high.
Grill radicchio on both sides until edges begin to char, set aside.
While radicchio is grilling, toast bread on both sides on the grill.
Step 3: Grill the flank steak
Season steak with salt and freshly ground black pepper and grill over direct heat for about 3 - 4 minutes each side for medium rare.
PREP TIP I think Anthony Bourdain said "put it on the grill and LEAVEITALONE!" Don't fiddle with it. Don't poke it, mash it down, or keep moving it around. This will ensure that the steak cooks perfectly and that you retain all of the juices to keep it and tender.
Step 4: Assemble the sandwich
While steak rests, spread mascarpone cheese onto one side of each slice of bread. Layer roasted red peppers on the bottom slice of bread, top with sliced steak, then radicchio and the top slice of bread.
Tips for grilled flank steak sandwiches
- Get the grill nice and hot.
- Grill the flank steak for 3 to 4 minutes per side for medium rare and no further. This is a very lean cut of meat, the longer you cook it the tougher it will get. Medium rare temperature is about 135 degrees F. Use a meat thermometer and remember that the steak will continue to cook a little bit while it rests.
- Don't move the meat around during the cooking process.
- Let the flank steak rest before slicing, then cut it against the grain.
- Swap out ingredients to make different versions of this flank steak sandwich all year long. If you don't like radicchio, swap it for grilled romaine. Not a fan of roasted red peppers? Try sun dried tomatoes instead! Endless possibilities!
There are 3 tricks to keeping flank steak tender. First, don't cook flank steak past medium rare. Second, once it's cooked, let it rest for at least 5 - 10 minutes so the juices stop running and go back into the meat. Finally, slice the meat against the grain, not with it. Slicing against the grain shortens the muscle fibers and allows the meat to fall apart and melt in your mouth when you chew it.
Yes! If you want to grill the flank steak ahead of time and make sandwiches later, that is perfectly fine. Store the grilled flank steak in the refrigerator for up to two days. Wait to slice the meat until you're ready to make sandwiches.
What to serve with flank steak sandwiches
A sandwich is definitely a main dish, but sometimes you also need a side. Try these ideas.
- What goes better with grilling and sandwiches than a classic Dill Potato Salad?
- This Green Bean Salad with Feta and Tomatoes doesn't require any cooking!
- You can't go wrong with a sandwich/slaw combination. Try my Mango Slaw for a fresh change of pace.
This steak sandwich is quick, easy and versatile!
- Flank steak cooks in about 8 minutes.
- No marinating the meat ahead of time, just season and grill.
- Change up the sandwich toppings and type of bread to suit your mood and the ingredients you have on hand.
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Flank Steak Sandwich Recipe
- 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
- Cut radicchio into wedges about 1 inch thick, drizzle with a bit of olive oil and balsamic vinegar, season with salt and pepper, and marinate for up to one hour.
- Slice roasted red peppers into strips.
- Place radicchio wedges on a medium-high grill, cooking until charred at the edges on both sides.
- While radicchio is grilling, toast bread on both sides on the grill.
- Season steak with salt and pepper and grill about 3-4 minutes each side for medium rare.
- While steak rests, spread mascarpone cheese onto one side of each slice of bread. Layer roasted red peppers on the bottom slice of bread, top with sliced steak, then radicchio and the other slice of bread.
- Get the grill nice and hot.
- Both cuts are from tough muscles, so don't cook past medium-rare.
- Cook 3 - 4 minutes per side to about 135 degrees F for medium rare.
- Don't move around during the cooking process.
- Slice thinly across the grain to ensure tenderness.