Corned Beef Sliders with Caramelized Onions
These delicious corned beef sliders feature tender corned beef, melty Swiss cheese, sweet caramelized onions, and a zesty mustard-horseradish sauce on Hawaiian rolls with a buttery pickling spice topping!
Equipment
- Large skillet
- Sheet pan
- Pastry brush or spoon
- Aluminum foil and parchment paper
Ingredients
- 1 package King's Hawaiian sweet rolls, 12 count
- 1 pound thinly sliced deli corned beef or leftover corned beef
- 12 slices Swiss cheese (about 8 oz or 1/2 lb.) *see note below
- 2 tablespoons butter
- 2 large onions thinly sliced
- 1 tablespoon brown sugar
- 1/2 teaspoon (2g) diamond crystal kosher salt (half if using table salt)
- 1/4 teaspoon black pepper (preferably freshly cracked)
Mustard Horseradish Sauce:
- 3 tablespoons Dijon mustard
- 2 tablespoons prepared horseradish, drained
- 1 tablespoon honey
- 1 tablespoon mayonnaise
For the Pickling Spice Butter Topping:
- 1/4 cup 4 tablespoons butter, melted
- 1 tablespoon pickling spice, coarsely ground *see note below
- 1 teaspoon Worcestershire sauce
- 1/2 teaspoon garlic powder
Instructions
- Prepare the caramelized onions: In a large skillet over medium-low heat, melt 2 tablespoons of butter.
- Add thinly sliced onions with a pinch of salt and cook slowly, stirring occasionally, for 30-35 minutes until golden brown. Add brown sugar, stir, and cook for another 5 minutes. Set aside.
- Make the mustard horseradish sauce: In a small bowl, combine Dijon mustard, horseradish, honey, and mayonnaise. Stir until well combined and set aside.
- Prepare the pickling spice butter topping: In a small bowl, combine melted butter, Worcestershire sauce, crushed pickling spices, and garlic powder. Stir well and set aside.
- Preheat oven to 350°F (175°C). Line a sheet pan with parchment paper.
- Without separating the rolls, slice the entire package of Hawaiian rolls horizontally in half. Place the bottom half in the prepared baking dish.
- Spread a thin layer of the mustard horseradish sauce on the bottom half of the rolls.
- Layer 6 slices of Swiss cheese on top of the sauce.
- Add a layer of corned beef, evenly distributing it across the rolls.
- Spread the caramelized onions evenly over the corned beef.
- Place the remaining 6 slices of Swiss cheese on top of the onions.
- Place the top half of the rolls over the cheese layer.
- Brush the pickling spice butter mixture generously over the tops of the rolls.
- Cover loosely with foil and bake for 15 minutes. , then remove the foil and bake for an additional 5-8 minutes until the tops are golden brown and the cheese is melted.
- Let cool for 5 minutes before slicing into individual sliders and serving.
Notes
- You can caramelize the onions up to 3 days ahead of time and store them in the refrigerator.
- *For the pickling spice, grind the spices using a coffee grinder and spice grinder, or a mortar and pestle.
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*Cheese Note:
I used imported Swiss (Emmental) for these sliders, sliced thin, because I’m not into overly cheesy bites. It’s a little bolder in flavor, melts like a dream, and the slices are longer and wider, so 6 slices were all I needed to cover the rolls. If you’re using domestic Swiss, which is milder and comes in smaller slices, go with 12 slices to get full coverage and that perfect melty pull in every bite.
