Heat oil in a large skillet over medium-high heat. Add tortilla triangles in batches of 6-8. Fry approximately 1 minute on each side or until golden and crispy. Transfer to a paper towel lined plate to absorb excess oil.  Set aside.

Place beans (undrained) and epazote leaves in a blender. Blend until smooth. Transfer mixture to a skillet over medium heat and add crema and salt.  Stir to mix well; about 8 minutes.

Divide fried tortilla triangles on four plates. Top with black bean sauce, a fried egg, epazote leaves, cotija cheese and onion rounds. Serve.