Bring a large pot of water to boil.
Place the entire bag of frozen beef barbacoa in the boiling water for 15 minutes.
While the water is boiling, prepare the rice and cut the veggies.
If you are making the optional crema, combine all ingredients in a blender until incorporated. Set aside.
To assemble the bowls place rice on the bottom of each bowl, top with black beans, corn, avocado, peppers and beef barbacoa. Squeeze with lime juice and top with cilantro-lime crema (optional)