1. Using a medium bowl, spread mashed avocado across the bottom to make a bottom layer.
2. Then, add the Greek yogurt on top, being sure to smooth as needed.
3. Once you have your base layers, continue to build your dip by adding the black beans, followed by tomatoes.
4. Finish this tasty dip off with shredded cheese and diced avocado if desired.
5. Toast pitas, and serve alongside dip.