Toss the cooked steak and the shredded cheese with the taco seasonoing.
Heat a skillet to medium-low heat and melt 1 tablespoon of the butter.
Spread desired amount of creamy jalapeno sauce on each tortilla.
Place one tortilla in the pan and place half the cheese, steak, and taco seasoning mixture on top. Top with another torilla.
Cook about 3 minutes on each side, or until the tortilla is golden brown and the cheese is melted.
Repeat for the remaining quesadilla.
Notes
Add some avocado: If you want to reduce the amount of cheese, you can add some mashed avocado to the quesadilla. It's still creamy and delicious! Don't omit the cheese completely; it helps hold the quesadilla together.
Use different cheese: While cheddar is one of the cheeses in Taco Bell's original recipe, a traditional Mexican cheese like queso Oaxaca or Chihuahua cheese would be a great alternative. You can also use a mix of different cheeses for more flavor.
Try a different meat: If you're not a fan of steak, you can use grilled chicken, turkey, or ground beef.
Make it dairy-free: Use vegan cheese, cooking spray, and coconut milk yogurt (to replace the sour cream) to make this recipe dairy-free. Choose a vegan cheese that melts well, as some brands don't melt as easily.