Heat the oil in a large skillet over medium-high heat until it shimmers. Add the onion and cook until tender and translucent, about 4 minutes. Add the tomatoes with the juice and cook for about a minute, stirring. Add the tomato paste and cook, stirring, for another minute. Add the beans, peppers, cumin, chipotle pepper, 1 teaspoon salt, and ½ teaspoon pepper. Let simmer, uncovered, for about 10 minutes, or until slightly thickened. Keep warm until serving.
Heat another skillet (cast iron is perfect) over medium-high heat. When hot, add the tortillas, one at a time, and cook until they soften and start to brown in spots. Remove from the skillet and keep warm. Repeat until all the tortillas are cooked.
Reduce the heat to medium, add the butter to the skillet, and let it melt. Crack the eggs into the skillet, season with salt and pepper, and cook 2-3 minutes or until desired degree of doneness.
To serve, place some of the tomato sauce on a pan, top with an egg, avocado slices, and cilantro and serve with the warm tortillas.