The key to a great weeknight meal is something that’s easy to prep ahead of time and comes together quickly. These open-faced sandwiches fit the bill, with grilled flank steak on crunchy bread that’s topped with spicy arugula, a few pickled red onions and a tasty parmesan mustard sauce giving you the ultimate easy dinner solution.
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I don’t eat a lot of steak but when I do it’s nearly always tenderloin so I’ve been wanting to do a recipe with a different type of steak. Enter the open-faced grilled steak sandwich!
These steak sandwiches make an excellent light summer or early fall dinner and are also a big hit as a party appetizer. Not doing carbs this week…or ever? No problem – ditch the bread and add a bit more arugula. Now you’ve got a mini steak salad!
But assuming you are into bread, pick a nice crusty bread and toast it just a little bit before you assemble the sandwiches. Sometimes I even scoop out a little bit of the center of the bread to make it easier for the toppings to stay on the bread.
Meal Prep Tips
If you want to start these as part of your weekly meal prep you can make the marinade the night before or even a day or two ahead of time and then throw the flank steak in the marinade before you leave for work. When you get home, just fire up your grill and take the steak out of the refrigerator. Grill and enjoy.
You can also grill the steak a day or two ahead of time and serve these as cold steak sandwiches. I’ve tried them that way a couple of times and they are delicious!
Both the pickled onions and the parmesan mustard sauce can also be made ahead of time so this recipe is a great one to add to your weekly meal prep plans.
Pickling red onion is really easy and I typically keep a jar of them in my refrigerator. I normally use this recipe from Gimme Some Oven but there are tons of options out there, all with slight variations, so give a couple a try until you find your favorite.
things you might want for this recipe
Weber iGrill 3 – If you have a Weber grill that is compatible with this thermometer I highly recommend investing in one. I’ve tested it out on this flank steak as well as burgers and chicken and it is spot on. No more guessing when food is done, just set the temperature on the app and your phone will tell you when to take the food off the grill!!
Open-Faced Grilled Steak Sandwiches
For the steak:
- ¾ pound flank steak, trimmed
- 3 tablespoons worstershire sauce
- 2 teaspoons dijon mustard
- ½ teaspoon lemon juice
- 1 garlic clove, minced
For the sauce:
- 2 tablespoons whole grain mustard
- 2 tablespoons olive oil mayonaise
- 1 tablespoon lemon juice
- 1 tablespoon olive oil
- 3 tablespoons grated parmesan cheese
- ½ teaspoon cracked pepper
For the sandwich:
- ⅓ cup pickled red onion
- ½ cup baby arugula leaves
- ½ baguette, cut into 3 pieces
- Marinate the steak. Mix the worstershire, mustard, lemon juice and garlic in a small bowl. Place the flank steak on a platter and pour the marinade over the steak, brushing to coat all sides. Marinate in the refrigerator for at least 2 hours.
- Make the sauce. Mix the whole grain mustard, lemon juice, mayo, olive oil, cheese and cracked pepper in a small bowl or jar. Refrigerate until ready to use.
- Preheat your grill to medium high heat, about 425°F.
- Grill the steak. Place the steak on the grill and grill for 5 minutes and then flip the steak and grill for another 5 minutes or until the steak reaches an internal temperature of 135°F (for medium rare). Remove the steak from the grill and let it rest for 10 minutes. Going at a slight diagonal to the grain of the meat, slice into thin slices.
- Assemble the sandwiches. Slice the baguette pieces lengthwise. Toast the baguette for a few minutes. Spread a bit of the parmesan mustard sauce on each baguette slice. Top with arugula leaves. Top with steak, pickled onions and more parmesan mustard sauce. Serve and enjoy!
- You can let the steak marinate for up to 24 hours