Preheat the oven to 350°F. Lightly grease or line a 9x13-inch baking dish.
Sauté the onions: Melt 1 tablespoon of olive oil in a large skillet over medium heat. Add the diced yellow onion and cook for 6–8 minutes, stirring occasionally, until softened and lightly golden.
Brown & season the beef with burger seasoning: Add the ground beef to the skillet and cook, breaking it into small crumbles as it browns. Sprinkle with 2–3 teaspoons of the Burger Seasoning and continue cooking until no pink remains.
Thoroughly drain any excess grease from the beef mixture. Without separating the rolls, slice the entire sheet of Hawaiian rolls horizontally using a serrated knife.
Place the bottom half of the rolls into the prepared baking dish. Arrange 6 slices of cheese evenly over the bottom rolls, covering as much surface as possible. This layer acts as a moisture barrier to help keep the bottoms from becoming soggy.
Evenly spread the seasoned ground beef mixture over the cheese.
Top with pickle slices.
Arrange the remaining 6 slices of cheese over the toppings, then place the top half of the Hawaiian rolls over everything.
Brush the tops evenly with the melted butter and sprinkle with the sesame seeds.
Cover loosely with aluminum foil and bake for 10 minutes. Remove the foil and continue baking for 5–8 minutes, or until the cheese is completely melted and the tops are golden brown.
Let the sliders rest for about 5 minutes before cutting along the roll lines into individual sliders.
Serve warm with extra Burger Sauce, yellow mustard and ketchup on the side for dipping.
Notes
Seasoning: Use about 2 teaspoons of Burger Seasoning per pound of ground beef.
Drain well: Remove as much grease as possible from the cooked beef to keep the bottom rolls from getting soggy.
Rolls: My Hawaiian Dinner Rolls make 15 sliders. A 12-count store-bought package works with the same filling and makes slightly meatier sliders.
Pickles: Add well-drained pickles before baking or leave them off for a cooler, crunchier topping afterward.
Sauces: Serve ketchup, mustard, and Burger Sauce on the side to avoid adding extra moisture.