Cut the tortillas into sixths and fry them in the oil in batches over medium-high heat until crisp and lightly golden, about 2 minutes a batch. Drain on paper and salt them lightly.
Broil the tomatillos, serranos, onion half and garlic on a tray until blistered and blackened in patches, about 6 to 8 minutes, turning once.
Blend the roasted vegetables with the cilantro and the salt until smooth.
Heat a tablespoon of the frying oil in a wide skillet, pour in the salsa, and fry it for 4 to 5 minutes, stirring, until it darkens and thickens.
Add the broth and simmer 5 minutes, until the sauce coats a spoon but still pours.
Fry the eggs in a separate pan to your liking.
Turn the heat under the salsa to low. Add the chips and fold them through for 30 to 60 seconds, no longer, until they are coated but still have bite.
Serve immediately, topped with a fried egg, crumbled queso fresco, a drizzle of sour cream and raw onion rings.