1. Prepare the Dijon-Mayo Spread: A Tangy and Creamy Base

1. Combine Ingredients: In a small bowl, combine the mayonnaise and 2 tablespoons of Dijon mustard.
2. Stir Well: Stir until the mixture is smooth and well combined.
3. Set Aside: Set the Dijon-mayo spread aside while you prepare the other components.

2. Prepare the Rolls: Creating the Slider Foundation

1. Slice Rolls: Using a serrated bread knife, carefully slice the package of slider buns in half horizontally, creating a top and bottom layer. Do not separate the individual rolls. You should have two large, connected slabs of rolls.
2. Place in Baking Dish: Place the bottom half of the sliced rolls, cut-side up, into a lightly greased 9×13 inch baking dish (glass or light-colored ceramic recommended).

3. Preheat the Oven and Prepare for Baking: Ensuring Even Cooking

1. Broil: Preheat your oven’s broiler to high with the rack in the second position down from the top (about 6 inches from the broiler element).
2. Toast Rolls: Place the baking sheet with both the top and bottom of the rolls, cut side up, under the broiler for 1-2 minutes. Keep a very close eye, as they can burn quickly. You want them lightly toasted.
3. Preheat for Baking: Preheat the oven to 350°F (175°C) with the rack in the middle position.

4. Assemble the Sliders: Building Layers of Flavor

1. Spread with Dijon-Mayo: Spread a little more than half of the prepared Dijon-mayo mixture evenly over the toasted bottom layer of rolls in the baking dish.
2. Layer Cheese and Ham:
   • Cheddar: Layer the slices of sharp cheddar cheese evenly over the Dijon-mayo.
   • Ham: Layer the thinly sliced deli ham over the cheddar cheese.
   • Swiss: Layer the slices of Swiss cheese over the ham.
3. Spread Remaining Dijon-Mayo: Spread the remaining Dijon-mayo mixture evenly over the toasted side of the top half of the rolls.
4. Top the Sliders: Carefully place the top half of the rolls, Dijon-mayo side down, over the Swiss cheese layer, aligning them with the bottom halves.

5. Prepare the Butter Topping: A Savory and Aromatic Glaze

1. Melt Butter: In a small bowl, melt ½ cup of unsalted butter.
2. Combine Ingredients: Stir in the Worcestershire sauce, poppy seeds, onion powder, and a pinch of kosher salt (if using) until well combined.

6. Brush and Bake: Achieving Golden-Brown and Melty Goodness

1. Pour and Brush Topping: Pour the melted butter mixture evenly over the assembled sliders. Use a pastry brush or basting brush to distribute the butter and poppy seeds evenly over the tops and sides of the rolls.
   • Tip: It’s okay if some of the butter pools around the sliders in the baking dish – this will add extra flavor to the bottom of the rolls.
2. Cover with Foil: Cover the baking dish loosely with aluminum foil.
   • Tip: Make sure the foil doesn’t touch the tops of the rolls directly, or they might stick.
3. Rest: Let the covered sliders stand for about 5 minutes to allow the flavors to meld.
4. Bake: Bake in the preheated oven for 20 minutes.
5. Uncover and Bake: Remove the foil and continue baking for another 5-10 minutes, or until the tops of the rolls are golden brown and crispy, and the cheese is melted and bubbly.
   • Tip: Watch the sliders carefully during the last stage of baking to prevent them from getting too dark.
   • Note: If using a dark-colored baking pan, reduce oven temp to 325F.

7. Cool and Serve: Enjoying the Irresistible Sliders

1. Cool Slightly: Let the sliders cool in the baking dish for a few minutes before cutting.
2. Cut into Sliders: Using a sharp knife, cut the connected rolls into individual sliders.
3. Serve Hot: Serve the Baked Ham and Cheese Sliders hot, with potato chips, fries, or your favorite sandwich sides.