If you took my advice and stayed at the Ucum (or listened to the voice of Beelzebub and chose the Holiday Inn in front of it), you won't have far to go for a decent breakfast. And that, essentially is what we want out of breakfast, no? Not gourmet triumphs: but decent. Filling. Cheap. Non-disgusting. Here you are, right on the corner across from the Ucum, the Pantoja.
Nothing fancy, but no hole in the wall, either. (There's a fine one of those two doors the other way from the Ucum) Wood tables and chairs with table cloths, not beer brand plastic. Family atmosphere (if you're lucky as I was, you'll catch Skeletor talking in Spanish on the inevitable TV). I had a cheese and ham omelette for $20 pesos and a large fruit plate (watermelon, cantalope, banana, and papaya) for $12. But about that omelette- it was actually a platter with veggie rice, salad, fries, and some fried black beans. Not to mention a big basket of sliced sourdough rolls they call bollilos in these parts. Not too shabby.
In the eveing you can eat well for less, also. Smoked pork chop with the full treatment for $28 pesos (yes, that's under $3) Steaks, seafood, etc.