Corned Beef Sliders Mustard

My brother showed up at my door last Sunday with three pounds of corned beef and a look that said I know what we're doing today. We'd been talking about recreating those sliders from the deli downtown for months, the ones with the butter-drenched tops and that perfect poppy seed crunch. The whole kitchen smelled like warm bread and mustard within twenty minutes.

Last Super Bowl, I put out a platter of these and honestly forgot about the main dish. Everyone kept drifting back to the kitchen, grabbing another slider, another, until the baking sheet was just crumbs. My friend Sarah finally asked if I'd mind terribly if she took home the remaining two that were somehow still sitting there.

Ingredients

• Sliced corned beef (450 g/1 lb): Ask your deli counter to slice it thin but not paper-thin, you want some chew here
• 12 slider buns or mini rolls: Soft buns work best, they soak up that butter mixture and stay tender
• 6 slices Swiss cheese, halved: Swiss melts beautifully and adds that mild nutty flavor that plays so well with corned beef
• Whole-grain mustard (4 tbsp): The texture here matters, those little mustard seeds pop between bites
• Mayonnaise (2 tbsp, optional): I always add this, it tames the mustard's sharp edge just enough
• Red onion (1/2 small, thinly sliced): Thin is key here, you want sweetness without that raw onion bite
• Dill pickle slices (12): One per slider is perfect, they cut through all that rich cheese and beef
• Unsalted butter (3 tbsp, melted): Unsalted lets you control the salt level since corned beef is already pretty salty
• Dijon mustard (1 tsp): This mixes into the butter for the tops, different from the whole-grain inside
• Garlic powder (1/2 tsp): Don't skip this, it makes the butter mixture taste like something special
• Poppy seeds (1 tsp, optional): These give you that classic deli slider crunch and look beautiful

Instructions

Preheat your oven:

Get it to 180°C (350°F) and line a baking sheet with parchment paper, trust me, cleanup is worth this step.

Prep the buns:

Slice all your slider buns in half and arrange the bottom halves on your prepared baking sheet like a little bun army.

Layer the fillings:

Start with corned beef on each bottom bun, add that halved Swiss cheese, a few onion rings, and crown it with a pickle slice.

Spread the tops:

Mix the whole-grain mustard with mayonnaise if you're using it, and spread it on the inside of each top bun.

Assemble and butter:

Place those tops on the sliders, then whisk together melted butter, Dijon, garlic powder, and poppy seeds until it smells like heaven.

Brush and cover:

Generously brush that butter mixture over every bun top, cover loosely with foil, and bake for 10 minutes.

Get golden:

Remove the foil and bake another 5 minutes until the cheese is bubbling and those bun tops are gorgeous and golden.

Save

These became my go-to whenever someone says they're stopping by and I have zero time to prep something impressive. I've started keeping slider buns in the freezer just for this exact scenario, thawing them while the oven heats up.

Make-Ahead Magic

You can assemble these entirely up to 24 hours before baking, just keep them covered in the fridge and add the butter mixture right before they go into the oven. I've done this for brunch and popped them in while everyone was having mimosas, timing it so they came out fragrant and golden right when hunger struck.

Bread Swaps That Work

Rye buns transform these into something that tastes like it came from a New York deli, while Hawaiian sweet rolls add this incredible salty-sweet contrast that people go crazy for. Once I used everything bagel sliders and the whole seasoning-on-the-outside thing made these next-level addictive.

Party Planning Perfection

These reheat surprisingly well at 160°C (325°F) for about 8 minutes, so you can make them in the morning and warm them up right before guests arrive. I've served these at everything from baby showers to game day, and they're always the first empty platter on the table.

• Cut the assembled slab of sliders into individual squares after baking for easy grabbing
• Set out extra mustard and some coleslaw for people who want to build their own perfect bite
• Have a baking sheet ready in a warm oven (about 90°C/200°F) to keep them hot if you're serving buffet-style

Save

There's something about pulling apart warm, cheesy sliders with friends that just makes a regular Tuesday feel like a celebration. Hope these bring that same joy to your table.

Recipe FAQs

→ What type of cheese complements corned beef sliders?

Swiss cheese pairs well, providing a mild, creamy texture that melts beautifully and balances the savory beef.

→ Can I use a different mustard variation for the topping?

Yes, Dijon or whole-grain mustard both enhance flavor; whole-grain adds texture and tanginess to the sliders.

→ How can I make the buns golden and flavorful?

Brushing a butter mixture containing garlic powder and poppy seeds on top before baking gives the buns a rich, golden crust.

→ Are there good alternatives to slider buns?

Mini rolls or rye slider buns work well, especially for adding a classic deli touch.

→ What sides pair well with these sliders?

Light-bodied red wines or crisp lagers complement the flavors, and sauerkraut adds an extra layer of zest if desired.