In a small bowl, mash up black beans until they are a thick paste.
In a frying pan, sauté the onion and pepper. Once cooked, add the veggie ground round and heat (do not overcook!)
In a round casserole dish place one tortilla shell on the bottom. Spread the black bean paste over the shell then add some of the "meat" mixture. Top with cheese and another tortilla. Continue layer until bean and meat mixture is used up.
On the top tortilla add the salsa and spread around. Sprinkle with cheese and green onion.
Bake at 375 degrees for 15-20 minutes, or until cheese is melted.