Steak and Caramelized Onion Quesadilla
Thinly sliced skirt steak, deeply caramelized onions, and pepper jack cheese in a butter-toasted flour tortilla. The caramelized onions take twenty-five minutes and cannot be rushed — that's also why this quesadilla tastes like something you'd order at a restaurant instead of something you made in fifteen minutes.
Ingredients
Meat & Protein
- 10 oz skirt steak or flank steak — can substitute leftover steak from the fridge, sliced thin
Produce
- 2 yellow onion halved and thinly sliced
- 2 garlic cloves minced
Dairy
- 2 cups pepper jack cheese freshly shredded
- 2 tbsp unsalted butter divided — 1 tbsp for onions, 1 tbsp for toasting tortillas
Pantry & Canned Goods
- 4 flour tortillas large, burrito size
- 1 tbsp olive oil divided
- 1 tsp Worcestershire sauce
Seasonings & Spices
- 0.75 tsp kosher salt divided
- 0.5 tsp black pepper
- 0.5 tsp garlic powder
- 0.5 tsp smoked paprika
Instructions
- Caramelize the onions: melt 1 tablespoon of butter with a splash of olive oil in a wide skillet over medium-low heat. Add the sliced onions and a pinch of salt. Cook, stirring every few minutes, for 25 to 30 minutes until deeply golden and jammy. Do not rush this with higher heat — the onions will brown on the outside and stay sharp on the inside. Add the Worcestershire sauce and minced garlic in the last 2 minutes, stir to combine, then remove from heat.
- While the onions finish, cook the steak: pat dry, season with salt, pepper, garlic powder, and smoked paprika. Heat remaining olive oil in a cast iron or heavy skillet over high heat until smoking. Sear the steak 2 to 3 minutes per side for medium-rare. Rest 5 minutes then slice as thin as possible against the grain. (Skip this step if using leftover steak — slice cold and proceed.)
- Build the quesadillas: lay a tortilla flat. Cover one half evenly with a quarter of the shredded pepper jack. Add a layer of sliced steak, then a layer of caramelized onions. Top with another quarter of the cheese. Fold the bare half over the filling and press firmly. Repeat with the second tortilla.
- Toast in a clean skillet over medium heat with a small pat of butter until golden brown and crisp on both sides, about 2 to 3 minutes per side. Press gently with a spatula while cooking. Rest 1 minute before cutting.
- Cut each quesadilla into 3 or 4 wedges. Serve with sour cream, guacamole, or salsa.
Notes
Leftover steak works perfectly here — the One-Pan Garlic Butter Steak Bites, Air Fryer Steak and Potatoes, or any cooked steak from the fridge. Slice it cold and thin and it heats through in the quesadilla without overcooking.
The cheese layer goes on first AND last — cheese on the tortilla, then steak, then onions, then more cheese. The bottom cheese layer adheres to the tortilla; the top layer seals everything together when it melts. Don't skip this.
Caramelized onions can be made up to 3 days ahead and stored in the fridge. If you have them ready, this quesadilla comes together in 15 minutes.
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