Boiling is a type of cooking method that involves heating a liquid to the point where bubbles form. There are different ways that eggs can be prepared, and boiling eggs is one way. "What it boils down to is this" is a saying that is expressing what the most important aspect of something is. In this case, "eggs taste good" is the most important aspect. 
This is a play on the word "boil". 
What it boils down to is this : eggs taste good .