Preheat oven to 350°F (175°C).
Slice the connected rolls horizontally, keeping them intact.
Place the bottom half of the rolls into a greased baking dish.
Spread mustard evenly, then layer pulled pork and Swiss cheese.
Place the top half of the rolls back on.
In a bowl, mix melted butter, brown sugar, garlic powder, onion powder, oregano, salt, and pepper.
Brush the butter mixture generously over the rolls, letting it seep between cracks.
Cover loosely with foil and bake for 15 minutes.
Remove foil and bake another 8–10 minutes until golden and melty.
Rest 5 minutes before pulling apart and serving.