Cheesy Skillet French Onion Meatball Sliders Step-by-step instructions

Before you start

Before starting, gather all ingredients. Slice the onions thinly and set aside. If using raw meatballs, cook them ahead of time or plan to sear them first.

Preheat the oven to 375°F (190°C) when ready to bake. Have the skillet and all components ready for assembly.

Instructions

Caramelize and Glaze

1. 1Caramelize the Onions
   Melt 3 tablespoons butter in a large skillet over medium heat. Add the sliced onions and cook, stirring occasionally, until they soften and begin to brown. Reduce heat to medium-low and continue cooking for 20–25 minutes, stirring every few minutes, until the onions are deeply caramelized and jammy. Stir in the Worcestershire sauce and beef broth, scraping up any browned bits. Simmer for 2–3 minutes until the liquid reduces slightly. Set aside.
   Look for Onions are dark golden-brown, soft, and the liquid has thickened into a glossy glaze.
   Tip Patience is key—cook low and slow to bring out the natural sweetness without burning.
2. 2Warm the Meatballs
   Add the meatballs to the skillet with the caramelized onions and pan juices. Toss to coat the meatballs evenly with the onion mixture. Cook over medium heat for 5–7 minutes, stirring occasionally, until the meatballs are heated through and glazed. If using raw meatballs, cook them fully in the skillet before adding the onions, ensuring they reach an internal temperature of 160°F (71°C).
   Look for Meatballs are glossy with the onion glaze and hot throughout.
   Safe temperature 160°F (71°C) internal temperature (ground meat)
   Tip If using raw meatballs, sear them first, then set aside while caramelizing onions.

The onions should be deeply browned, soft, and glossy. The Worcestershire and broth will have reduced into a sticky glaze.

The meatballs should be heated through and coated with the onion mixture, with no raw spots.

Assemble and Top

3. 3Assemble the Sliders
   Preheat the oven to 375°F (190°C). Without separating the rolls, slice the entire slab of Hawaiian rolls in half horizontally. Place the bottom half in a cast-iron skillet. Arrange the meatballs evenly over the rolls, placing one meatball on each roll bottom. Spoon any remaining caramelized onions over the meatballs. Sprinkle the shredded Gruyère cheese generously over the top, covering the meatballs and onions completely.
   Look for The rolls are snugly packed in the skillet, topped with meatballs and a thick layer of cheese.
   Tip Keep the rolls connected for easy assembly and a beautiful pull-apart presentation.
4. 4Top with Garlic Butter
   In a small bowl, mix the melted butter with the minced garlic. Brush the cut side of the top half of the rolls with the garlic butter. Place the top half over the cheese-covered meatballs, buttered side down. Brush the outside of the rolls with any remaining garlic butter.
   Look for The tops are lightly coated with garlic butter, which will help them toast golden.
   Tip Use a pastry brush for even coverage and a rich, buttery crust.

The rolls are neatly arranged in the skillet with meatballs and onions evenly distributed. The cheese should completely cover the filling. The top rolls are brushed with garlic butter, ready for baking.

Bake and Serve

5. 5Bake Until Golden and Bubbly
   Place the skillet in the preheated oven and bake for 12–15 minutes, until the cheese is melted and bubbly and the roll tops are golden brown and toasted. If desired, broil for the last 1–2 minutes for extra browning, watching carefully to prevent burning.
   Look for The cheese is bubbling at the edges and the tops are deeply golden.
   Tip Let the sliders rest for 5 minutes before serving to allow the cheese to set slightly.
6. 6Pull Apart and Serve
   Remove the skillet from the oven and let it cool for a few minutes. Use a spatula to lift individual sliders or pull them apart by hand. Serve warm, with extra caramelized onions on the side if desired.
   Look for The cheese stretches as the sliders are pulled apart.
   Tip Serve directly from the skillet for a rustic, communal presentation.

The rolls are golden and toasted, the cheese is bubbly and lightly browned. Pulling a slider apart should yield long cheese strings. The texture is crisp on top, soft inside, with a savory, cheesy center.

Common mistakes

Avoid rushing the caramelization—cooking the onions over high heat will burn them before they become sweet and jammy.

Also, don’t overstuff the rolls; too many meatballs can make them difficult to pull apart. Finally, watch the broiler if using it, as the rolls can go from golden to burnt quickly.

How to tell it’s done

The sliders are done when the rolls are golden brown and toasted on top, and the cheese is fully melted and bubbling around the edges.

The internal temperature of the meatballs should be at least 160°F (71°C) if they were raw. Let the skillet rest for 5 minutes before serving.

• Ground meat: 160°F (71°C) in the thickest part