Preheat your oven to 350°F and line a baking sheet with parchment paper (because nobody likes stuck-on cheese cleanup).

Grab a bread knife and slice the rolls in half horizontally while keeping them connected — this makes assembly a breeze. Place the bottom half on your prepared baking sheet.

Start layering: first the ham, then the salami, and finish with pepperoni for that classic Italian sub flavor. Add a layer of provolone cheese, then sprinkle on a bit of Italian seasoning to bring it all together. Top with the chopped tomatoes, red onions, and pepperoncini peppers. Place the top buns back on. (You can add the shredded lettuce too if you want it warmed. I add it in after sliders have baked in the oven so it stays crisp.)

In a small microwave-safe bowl, combine the butter, dijon mustard, garlic powder, and Italian seasoning. Microwave for about 10 seconds, just until melted, and stir it all together.

Brush that buttery mixture evenly over the tops of the rolls and sprinkle a little parmesan cheese over for good measure.

Tent with foil and bake for 15–20 minutes, until the cheese is melted and everything smells amazing. Remove the foil and bake for another 5 minutes if you want those tops perfectly toasted.

Take the sliders out, lift off the top buns, and add the shredded lettuce (if you saved it for now) for that cool crunch. Pop the tops back on and serve warm.