Bourbon-marinated Flank Steak Hoagies with Horseradish Aioli

A few hours soaking in a bourbon bath intensifies the meatiness of the flank steak at the heart of this amazing sandwich. Grilled onions, melted asiago cheese and horseradish aioli make it absolutely luscious. We like using long pretzel rolls so the hoagies can easily be sliced and shared with guests for any barbecue.

By Russ Faulk, Kalamazoo Outdoor Gourmet
Serves 8
Image of Bourbon-marinated Flank Steak Hoagies with Horseradish Aioli

  • 2 pounds flank steak
  • 1-1/2 cups bourbon
  • 1/4 cup soy sauce
  • 1/4 cup extra-virgin olive oil
  • 1 large shallot, minced
  • 4 cloves garlic, crushed
  • 2 tablespoons prepared horseradish
  • 1/2 cup good-quality mayonnaise (we use Sir Kensington’s)
  • 1 red onion, thinly sliced
  • Fine gray sea salt
  • 2 pretzel rolls, about 11 inches long, sliced lengthwise
  • 4 ounces asiago cheese, sliced
  • Baby arugula

Score both sides of the flank steak in a cross-hatch pattern (about 1/8 inch deep and 1/4 inch apart) to increase the surface area for the Maillard reaction while grilling.

Whisk together the bourbon, soy sauce, olive oil and minced shallot to make the marinade. Seal the steak in a ziplock bag with the marinade and refrigerate for 4 hours.

To make the horseradish aioli, stir together the garlic, horseradish and mayonnaise. Cover and refrigerate for at least 1 hour to let the flavors combine.

Prepare the grill for direct grilling over high heat, with an indirect grilling zone at about 450°F. For a Kalamazoo K750 Hybrid Fire Grill, the ideal setup is a hot fire under one plancha surface and one meat surfacenext to each other. Place an additional meat surface in the indirect zone.

Grill the onion slices on the plancha surface (or on a cast-iron griddle or skillet) over the fire with a drizzle of olive oil. Cook, turning occasionally, until caramelized, about 15 minutes. You can start grilling the steak before the onions are done, but they should be mostly cooked  first.

Remove the steak from the marinade and discard the marinade. Season the steak with sea salt.

Cut the pretzel rolls in half and quickly toast the  insides over the fire, then remove from the grill. Use a rubber spatula to spread the horseradish aioli on the insides of each roll, then cover the bottom half of each roll with the sliced asiago cheese. Place the dressed rolls back on the grill, insides facing up, in the indirect grilling zone to melt the cheese, and continue toasting the rolls.

Grill the steak on the meat surface over the hot fire, closing the grill hood some of the time to help melt the cheese. Cook the steak to medium, about 8 minutes total grilling time. Rotate 90 degrees on the grill grate after 2 minutes, flip after 4, and rotate again after another 2. Once done, transfer the steak to a cutting board to rest for 4 minutes.

Remove the rolls from the grill and layer the caramelized onions on top of the cheese. Thinly slice the steak across the grain and layer it over the onions. Top with arugula and the tops of the rolls to finish the hoagies.