Heat 1 tablespoon of butter and 1 tablespoon vegetable oil in a large pan over medium-high heat.
Sprinkle onion and peppers with 3/4 teaspoon seasoned salt and 1/4 teaspoon pepper. Place onions and peppers in heated pan and cook 6 to 8 minutes. Place in a bowl and set aside.
If necessary, add a little more oil to the pan. Place over medium-high heat. Sprinkle steak with 1/2 teaspoon seasoned salt, 1 teaspoon steak seasoning, and 1/4 teaspoon pepper.
Cook steak until seared, about 1 to 2 minutes per side. If you like your steak well done, cook a little longer. Place steak in bowl with onions and peppers.
Add 1 tablespoon of butter to pan and cook mushrooms until golden. Transfer to the bowl with steak, onions, and peppers.
Wipe the pan clean. For each quesadilla add about 1 teaspoon oil and 1 teaspoon butter to the pan. Place over medium heat.
For each quesadilla, place about 3 slices cheese on one half of tortilla. Top cheese with steak, onion, and pepper mixture, using desired amount. Layer 3 more slices of cheese on top of filling and fold tortilla in half.
Cook in heated pan until golden and crispy on each side. Repeat with remaining tortillas.
This recipe originally appeared on spicysouthernkitchen.com