Place the steak in a glass dish. Sprinkle the steak on both sides with salt and pepper. Let stand at least 15 minutes and up to 1 hour to tenderize, turning the steak occasionally.
Heat the oil in a large, heavy skillet over high heat. Add the steak and saute to desired doneness, about 3 minutes per side for rare. Transfer the steak to a cutting board. Let rest 5 minutes. Slice thinly across the grain.
Place 4 tortillas in the skillet with the pan juices and heat over medium-high heat, working in batches if necessary. Place 1/2 cup cheese on top of each one and top with 4 ounces sliced meat. Place the remaining 4 tortillas on the top. Cook until the cheese start to melt, about 2 minutes. Flip and cook until golden and the cheese is melted, another 2 minutes on the other side.
Remove the quesadillas from the skillet. Peel open the quesadilla and spoon about 1/2 cup Roasted Tomatillo and Apple Salsa on top. Close the quesadilla and slice into quarters. Serve with Eva's Chunky Guacamole.
Roasted Tomatillo and Apple Salsa:
Preheat the oven to 350 degrees F.
Place the tomatillos, apples, garlic, onion and jalapenos on a baking sheet. Toss with the olive oil, 2 teaspoons salt and 1 teaspoon pepper and roast until the tomatillos are softened and slightly charred, about 20 minutes. Peel the garlic. Puree all the ingredients in a blender until smooth. Season with salt and pepper. Makes 3 1/2 cups.
Eva's Chunky Guacamole:
A viewer, who may not be a professional cook, provided this recipe. The Food Network Kitchens chefs have not tested this recipe and therefore, we cannot make representation as to the results.
In a large bowl, place the avocados, tomatoes, onion, cilantro, serrano, lemon juice, and salt, to taste. Stir gently until well combined. Transfer to a serving bowl and serve.
Cook' s Note: To keep the guacamole from turning brown, press a pit from one of the avocados into the center of the dish. Remove it before serving.