Preheat the oven to 350 degrees. Coat a flour tortilla with olive oil cooking spray. Place the flour tortilla into an ovenproof bowl or tortilla baking dish.
Bake for 10-15 minutes, or until golden brown.
Marinate flank steak for at least 6 hours up to 24 hours. Remove the steak from the refrigerator 20 minutes before cooking.
Heat a grill pan over medium-high heat and spray with cooking spray. Once the pan is really hot, add the flank steak and cook for 3-4 minutes per side or until your desired degree of doneness.
Place the steak on a cutting board. Allow the meat to rest for at least 5-7 minutes before slicing thinly against the grain. Slice the meat into bite-sized pieces.
Layer the warm spicy pinto beans, flank steak, lettuce, avocado, cherry tomatoes, black olives, red onion, chopped cilantro, green onion, and cotija cheese.
Serve with salsa, hot sauce, and sour cream. Enjoy.