Heat the olive oil in a medium saute pan set over medium heat. Add the onion and saute for 2-3 mins.
Warm the tortillas in the microwave until pliable, about 15 seconds.
Lay one tortilla down and spread 1/4 cup of the black bean spread along the center.
Next scatter pico de gallo, shredded cheese, avocado (if using), Romaine lettuce, cilantro, and a squeeze of lime juice over the top.
Black bean spread yields 1 1/2 cups.