Fry corn tortillas in 1-inch of hot oil until crispy. Set aside on paper towels to drain excess oil. Warm the black beans in a saucepan over medium heat. Add tomatoes, onion, cilantro and salt and pepper to saucepan. Reduce sauce over medium heat until flavors meld and ingredients come together.
Fry eggs over-easy or over-hard in fry pan.
Plate corn tortillas. Top with black beans. Place eggs over black beans. Add rancheros sauce on top of eggs. Garnish top with avocado, sprig of cilantro and a side of sour cream.