Start with desired amount of leftover cachupa. Using a mesh sieve or slotted spoon, drain off any liquid. Discard the liquid and set the cachupa aside. Don't worry if the cachupa maintains some of its liquid or appears wet even after you drain the liquid off. The moisture will be absorbed during the cooking process.

Heat 2-3 tablespoons of extra-virgin olive oil in a large skillet over medium heat. Add the diced onions to the skillet and toss them until they're fragrant and start to look clear. 

Add the cachupa to the skillet and turn the heat up slightly. Cook for about 10-15 minutes (longer depending on the amount and how much broth is remaining). You'll notice the liquid bubble and dry up as the cachupa cooks. When it's ready, you'll end up with a mixture that resembles hash. If your cachupa contains  root vegetables, check to make sure they are warm in the center.

Cut the flame from under the skilley and transfer the cachupa guisado to a covered dish or bowl. Carefully wipe the skillet out using a few paper towels. Grease the skillet using vegetable oil or cooking spray,  and turn the flame back on. Fry the the eggs to your liking (either sunny side up, or over-easy, medium or hard).

Plate each dish with a generous portion of cachupa guisado. Place 1 or 2 fried eggs on top, and serve.