Prepare the garnish at least a half hour before making the sopitas. In a bowl, combine the red onion with the lime juice, vinegar, oil, and salt. Mix and let it sit and macerate.
To make the sopitas:
In a large saute pan, add the chilorio fat and heat over medium-high heat. Once very hot, add the broken corn tortillas and let them heat, toast, and season, stirring occasionally, for about 4 to 5 minutes. Add the onion and Anaheim chiles, and cook for a couple minutes. Add the tomatoes and cook for 4 to 5 minutes, until completely softened.
Incorporate the prepared chilorio and cook for a couple more minutes. Pour in the beaten eggs and cook, stirring occasionally, until set as in messy scrambled eggs. Serve, topped with avocado, the red onion garnish, and, if you wish, a salsa of your choice.