Pastrami, Caramelized Onion, and Gruyère Sandwich

Pastrami Sandwich Recipe

Onion rye, sliced sourdough, or challah would all be great breads for this sandwich. At Macrina, we often feature it on our pretzel knot roll, a fairly dense roll made with the addition of a little rye flour, then topped with coarse salt, poppy seeds, and sesame seeds. The combination of these flavors with the American favorite delicacy of thinly sliced peppery pastrami plus sweet caramelized onions and nutty Gruyère cheese is terrific.–Leslie Mackie

LC A Proper Pastrami Sandwich Note

Not every slice of meat slapped between a couple slices of bread qualifies as a sammich. But this one does. (Don’t even get us started on that annoying trend of referring to a sandwich as a sammie. Sheesh.) In addition to qualifying as supper, this hearty little number also does a darn good job of qualifying as a brown-bag lunch, one that’ll at least give you something to look forward to all morning.

Pastrami Sandwich Recipe

  • Quick Glance
  • 25 M
  • 45 M
  • Makes 4 sandwiches


  • For the caramelized onions
  • 4 tablespoons (2 ounces) unsalted butter
  • 2 medium yellow or Walla Walla onions, cut into 1/8-inch slices
  • 1 teaspoon chopped thyme leaves
  • 1/4 teaspoon crushed red pepper flakes (optional)
  • Kosher salt to taste
  • For the mustard aioli
  • 1 large egg yolk
  • 1/2 teaspoon finely chopped garlic
  • 1 1/2 teaspoons fresh lemon juice
  • 1 tablespoon plus 1 teaspoon Dijon-style mustard
  • 1/2 cup canola oil
  • Kosher salt to taste
  • For the sandwiches
  • 4 pretzel rolls or other sandwich rolls
  • 2 tablespoons unsalted butter, at room temperature
  • 10 to 12 thin slices (about 14 ounces) good-quality pepper-crusted pastrami
  • 4 ounces Gruyère cheese, thinly sliced


  • Make the caramelized onions
  • 1. Melt the butter in a large nonstick skillet over medium-low heat. Add the onions and toss to coat. Cook until the onions have softened, about 5 minutes, and add the thyme and red pepper flakes, if using. Continue caramelizing the onions, stirring them frequently so they brown evenly, for up to 60 minutes or more. (If the heat is too hot, the onions will burn, so slow it down and take some time to enjoy the process.) Season to taste with salt. Transfer the onions to a large bowl and set aside.
  • Make the mustard aioli
  • 2. Whisk the egg yolk, garlic, lemon juice, and mustard in a medium bowl to thoroughly combine. Start adding the canola oil, just a few drops at a time, whisking constantly, until the mixture begins to emulsify. As it thickens, continue adding the oil in a slow stream, making sure each addition is thoroughly blended before adding more. Season to taste with salt. Cover the aioli and refrigerate until needed.
  • Assemble the sandwiches
  • 3. Position a rack in the center of the oven and preheat to 350°F (176°C). Line a rimmed baking sheet with parchment paper.
  • 4. Cut each roll in half horizontally. Butter the cut sides of the rolls and place them, cut side down, on the baking sheet. Toast the rolls in the oven for 3 to 5 minutes, until the butter is melted and the rolls are warm.
  • 5. Flip each roll over so that the cut side is up. Spread each side with some mustard aioli. Place equal amounts pastrami on the bottom half of each roll, folding it up to only slightly overhang. Next, divvy the caramelized onions among the sandwiches, layering them on the pastrami. Place the Gruyère on the top halves of the rolls. Return the sandwiches, still open-faced, to the oven for 5 minutes, or until the cheese is melted and the pastrami is warm to the touch.
  • 6. Sandwich the halves together and, if desired, cut on the diagonal with a serrated knife. You can take it from here.
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