Wrap tortillas in aluminum foil and heat in a 350º F oven while you prepare beans and fry eggs.

In the bowl of a food processor, combine 1 1/2 cups black beans, lime juice, cumin, cayenne and salt. Process until smooth. If necessary, add broth, 1 tablespoon at a time, to achieve an even consistency. Transfer the mixture to a bowl or saucepan and mix in the remaining 1 1/2 cups beans. Set aside.

In a large skillet, melt butter over medium heat. Gently crack eggs into the pan. Season with salt and pepper and let cook until the white is fully cooked through but the yolk is still soft. Cook eggs in batches if necessary. Meanwhile, heat bean mixture until warmed through, either in the microwave or on the stove.

Place each tortilla on a plate. Spoon some of the bean mixture over the top and sprinkle with shredded cheese. Top each tortilla with a cooked egg. Top with salsa, sour cream, hot sauce and avocado as desired. Garnish with cilantro.