Before You Get Started

The quick pickle relish only takes about 15 minutes and can be made several days ahead — it gets better as it sits. Use a sharp knife or mandoline to get thin, even slices on the cucumber and onion. If you can find pretzel slider buns, they add the perfect salty chew; brioche or potato rolls work well too. 

Steps

• Step 1

  Make the quick pickle relish: In a small saucepan over medium heat, combine the apple cider vinegar, sugar, mustard seeds, celery seeds, salt, and red pepper flakes. Bring to a simmer, stirring until the sugar dissolves. Add the diced cucumber and onion, stir to combine, and remove from the heat. Let cool for at least 15 minutes. The relish can be made up to 5 days ahead and stored in an airtight jar in the refrigerator. 

  Ingredients

  • 1/2 Cup apple cider vinegar

  • 2 Tablespoon granulated sugar

  • 1 Teaspoon yellow mustard seeds

  • 1/2 Teaspoon celery seeds

  • 1/2 Teaspoon kosher salt

  • 1/4 Teaspoon red pepper flakes

  • 1 Medium Persian cucumber, finely diced

  • 1/2 Small white onion, finely diced

• Step 2

  Set grill temperature to 350°F and preheat 15 minutes.

• Step 3

  Make the brown butter topping: In a small bowl, stir together the melted butter, black pepper, coriander, brown sugar, garlic powder, and onion powder. Set aside. 

  Ingredients

  • 4 Tablespoon unsalted butter, melted

  • 1/2 Teaspoon freshly ground black pepper

  • 1/2 Teaspoon ground coriander

  • 1/2 Teaspoon light brown sugar, packed

  • 1/4 Teaspoon garlic powder

  • 1/4 Teaspoon onion powder

• Step 4

  Slice the connected sheet of pretzel rolls in half horizontally. Place the bottom halves in a large baking dish or on a sheet tray. Spread the spicy brown mustard evenly over the bottom halves. 

  Ingredients

  • 12  pretzel slider rolls, kept connected if possible

  • 3 Tablespoon spicy brown mustard

• Step 5

  Layer the pastrami evenly over the mustard. Spoon the pickle relish over the pastrami, distributing it evenly. Lay the Swiss cheese slices over the relish to cover. Set the top halves of the rolls back on. 

  Ingredients

  • 1 Pound pastrami, thinly sliced

  • 12 Slices Swiss cheese

• Step 6

  Brush the tops of the rolls generously with the spiced butter mixture. Transfer the baking dish to the grill. Cook until the cheese is fully melted and the tops of the rolls are golden and glossy, about 15 to 20 minutes. 

  00:20

  350 ˚F / 177 ˚C

• Step 7

  Remove the sliders from the grill. Slice between the rolls to separate them. Pull one away from the group for a dramatic cheese pull, and serve immediately with any remaining spiced butter on the side for dipping. 

  Pro Tip

  Hardwood: Hickory adds a subtle smokiness that echoes the deep, cured flavor of the pastrami. 

  Make-Ahead: Assemble the sliders (without the butter topping) up to 4 hours ahead, cover, and refrigerate. Brush with the butter mixture just before placing on the grill.