This steak fajita quesadilla is filled with boldly marinated, perfectly grilled steak, melty cheese, and caramelized onions, all tucked inside a crispy, golden tortilla and served with fresh, classic toppings.
Mix together the ingredients for the marinade in a medium-sized bowl. Place the steak in a large freezer baggie or a shallow dish and pour the marinade over it. Seal the baggie (or cover the dish) and refrigerate for at least 30 minutes, or even better, 2 to 3 hours (no more than 4 hours).
½ cup lime juice, 3 cloves garlic, 3 tablespoon cilantro, 2 tablespoon vegetable oil, ½ teaspoon red pepper flakes, 1 lb skirt steak
Meanwhile, combine the fajita seasoning in a small bowl. Cover and set aside.
1 tablespoon cornstarch, 2 teaspoon chili powder, 1 tablespoon salt, 1 teaspoon smoked paprika, ½ teaspoon onion powder, ½ teaspoon garlic powder, ½ teaspoon ground cumin, ¼ teaspoon ground cayenne
Grill the Seak and Prepare the Quesadillas
Add the pork lard (or vegetable oil) to a medium skillet over medium heat. Add the onions and sauté for 15 minutes. Stir in the soy sauce, and sauté for another 10 to 15 minutes, until very soft and starting to darken. Set aside (this can be done up to 1 day in advance).
2 large onions, 2 tablespoon pork lard
Remove the steak from the marinade, shaking off excess. Discard the marinade.
Liberally sprinkle the steak all over with the fajita seasoning.
Prepare your grill for direct heat. Add the skirt steak over direct heat and cook for about 5 minutes per side, or until an internal temperature of 135 to 140°F for medium. Remove from the grill and let the meat rest on a cutting board for 5 to 10 minutes. Slice the meat into thin strips, against the grain. If desired, cut the strips into smaller bite-sized pieces. Set aside.
Preheat oven to 225°F.
Heat about 1 tablespoon of oil in a large skillet, preferably non-stick, over medium heat. Place a tortilla in the skillet and spin it around to fully coat the underside with the oil. Place about ½ cup of shredded cheese on one half of the tortilla. Top that with a layer of the chopped steak fajita meat. Spoon on a thin layer of caramelized onions. Top with ¼ cup of cheese. Fold the other half of the tortilla over and cook until the underside is brown and starting to crisp up.
vegetable oil, 2 flour tortillas, 2 cups Monterey Jack cheese
Flip the quesadilla (it will resemble a large soft flour taco) and cook until browned on the other side. Keep warm in the oven (on a baking sheet) while you prepare the other quesadilla.
Use a sharp knife (or pizza cutter) to cut the quesadillas into three triangles. Serve at once with sour cream, pico de gallo, and guacamole.
fresh pico de gallo, sour cream, homemade guacamole
Video
Notes
NOTE:Watch the video in the recipe card for visual guidance.
Seasoning & Salt: If using a store‑bought fajita seasoning, check whether it contains salt before adding extra; our homemade fajita seasoning already includes salt.
Marinating Time: A few hours is ideal for flavor without compromising texture; avoid overnight marinating due to the lime juice.
Cheese Tip: Shred cheese fresh for the smoothest melt and best coverage.
Steak Slicing: Always slice the steak thinly and against the grain for maximum tenderness.
Skillet Cooking: Use a little oil in the skillet to achieve a crispy, golden tortilla.
Heat Level: Adjust spice to taste by increasing or decreasing the red pepper flakes or serving with a spicier salsa.
Serving Timing: Quesadillas are best served immediately while the tortillas are crisp and the cheese is fully melted.