1/4cupfinely shredded cheese, Asadero, quesadilla, or your preference
grilled Carne Asada, sliced
red onion, slices
spinach leaves, optional
Make Carne Asada:
In a bowl, combine the butter, tequila, lemon and lime juice, thyme, serrano, garlic, cilantro, and onion and mix well.
Place steak in a large Ziploc bag and pour the marinade over beef. Zip up the bag and massage marinade around so that the beef is well covered. Let stand at room temperature for 30 minutes or in the refrigerator for up to 2 hours.
Preheat a grill or grill pan to high. Season steak with salt and pepper. Grill the steak for 5 to 7 minutes per side for medium-rare. Let rest 10 minutes, and then slice the meat against the grain into 1/2-inch pieces.
Place a dry griddle or cast-iron skillet over medium-high heat. Place a tortilla on the skillet and sprinkle with cheese. Add 2 to 4 strips of carne asada, red onion, and spinach (if desired). Top with more cheese. Place another tortilla on top. Cook until light golden, about 2 to 3 minutes or until cheese melts. Flip over and cook until golden brown. Cut each quesadilla into wedges.
Serve warm and, if desired, with salsa.
The meat can be served alone or sliced and used in tacos, burritos, or quesadillas. Carne asada can be purchased from meat markets either prepared (preparada, i.e., already marinated) or not (no preparada). Feel free to cheat and buy preparada.