Allow steaks to rest at room temperature to take the chill off of them. Pat the steaks with paper towels to remove any juices. Preheat cast-iron skillet or griddle over medium-high heat.
Place ancho and stock in a small pot, bring to boil then simmer a few minutes over low heat to soften the pepper. Pure softened pepper and stock in food processor, return to pot and combine with tomato sauce, salt and pepper.
Meanwhile, mix the juice of lime or lemon with garlic paste. Add the finely diced avocado, tomato, pepper, red onion and herb of choice to the bowl; season with a healthy pinch of salt and gently combine with fingertips or fork.
Rub a little drizzle of oil into a cast iron skillet or griddle and cook steaks 3 minutes on each side for medium-rare meat and 5 minutes on each side for medium-well. Let the meat rest to allow the juices to redistribute.
While meat cooks, heat a large nonstick skillet over medium-high heat with 1 tablespoon oil, add tortillas 1 at a time and cook to crisp, 30 seconds on each side. Drain and reserve on paper towels and reduce heat on pan to medium low. Add the butter. When hot, add eggs and gently cook. For eggs up, cover pan loosely with foil for 2 - 3 minutes. For over medium, cook eggs 2 minutes on each side. For over hard, cook 3 minutes on each side. Season eggs with salt and pepper.
To serve, thinly slice steaks on angle against the grain of the meat. Arrange the sliced steaks on each tortilla on individual plates and top with ancho sauce, egg and lots of fresh guac-salsa.