Grilled Balsamic Flank Steak With Peppers and Onions

Grilled Balsamic Flank Steak With Peppers and Onions
Photo: Petrina Tinslay
Prep Time:
25 mins
Total Time:
1 hrs 45 mins
4 to 6 Serves

Flank is a flavorful, lean cut of steak that's sliced thin and served. Make the deep, savory marinade ahead of time and let it work its magic on the meat for up to two days in the fridge. It makes party time a cinch, as the steak cooks in just 10 minutes (and this recipe can easily be doubled—or tripled to feed a crowd.)


  • 1 1/4 to 1 1/2 pounds flank steak, patted dry and pierced at approximately 1 1/2-inch intervals with the tines of a fork

  • Kosher salt and freshly ground pepper

  • ¼ cup balsamic vinegar

  • 1 tablespoon Worcestershire sauce

  • 2 teaspoons ground mustard

  • 2 tablespoons light-brown sugar

  • 1 tablespoon extra-virgin olive oil, plus more for grill

  • 3 rosemary sprigs

  • 1 large sweet onion, such as Vidalia, cut into scant ½-inch-thick rounds

  • 2 red or orange bell peppers, stems, ribs, and seeds removed, cut into scant ½-inch-thick rounds

  • Crusty bread, for serving (optional)


  1. Generously season steak with salt and pepper. In a large resealable bag, combine vinegar, Worcestershire, mustard, brown sugar, and oil. Rub rosemary sprigs between your palms for a few seconds to release oils, then transfer to bag. Add steak, onion, and bell peppers; remove excess air from bag, seal, and shake until marinade evenly coats meat and vegetables. Refrigerate at least 12 hours and up to 2 days.

  2. Remove steak and vegetables from refrigerator 1 hour before grilling. Preheat grill for direct-heat cooking. Brush grates with oil. Using tongs, remove steak from bag, allowing excess marinade to drip back in. Grill, turning a few times, until charred in places and a thermometer inserted into thickest part registers 125 degrees for medium-rare, 8 to 12 minutes, depending on thickness. Transfer to a plate; tent with foil and let stand at least 10 minutes before slicing. Meanwhile, remove vegetables from marinade and grill, turning a few times, until charred in places and tender, 10 to 12 minutes. Toast bread on grill just until charred and crisp in places, about 1 minute a side. Thinly slice steak; serve with vegetables and bread.

Cook's Notes

This recipe can easily be doubled or tripled to feed a larger crowd. You can also serve the steak and vegetables in soft hoagie rolls, drizzled with more oil and balsamic vinegar.

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