
Heat up a medium skillet over medium-high heat and add the vegetable oil.
Add the diced onion and bell pepper to the skillet and cook for 3-5 minutes or until the vegetables are tender (see tip #1). Add salt and pepper according to taste. Set aside when cooked.
Heat a separate large skillet or comal over medium heat. Place a flour tortilla and layer the ingredients on half of it: start with shredded cheese, sauteed veggies, then meat. Make sure to spread everything evenly.
Fold the other half of the tortilla over the steak mixture, pressing down gently.
Repeat the process with the remaining tortilla, veggies, cheese, and asada mixture.
Cook the tortilla for 2-3 minutes on each side or until the cheese is melted and the tortilla is lightly browned and crispy.
Cut the steak quesadillas into wedges and serve hot.