Catherine, there is no real recipe. It one of those where I eyeballed the ingredients so let me try to tell you what I did.
I used about 12 tomatillos and boiled them with about 5 serrano chiles. When the tomatillos changed color I removed them from the water with a slotted spoon. I put the tomatillos and serranos in a blender with some of their water, in batches, with a chopped white onion, a bunch of cilantro, some lime, half a bunch of chopped epazote and whirled it until smooth.
I put oil in a pan and heated it and returned the tomatillo sauce to the pan to “fry”. As the foam develops I skimmed and removed it. This takes a while to allow the sauce to thicken so it isn’t watery.
I chopped some corn tortillas (a lot of them) into small pieces and fried them until almost crispy. I put them on individual plates and then I fried eggs. Once the eggs were fried I placed them on the beds of tortilla pieces and covered the whole thing with the tomatillo sauce and then crumbled queso cotija cheese over it and finished it with a dollop of mexicana crema.