In a medium sized bowl, whisk together the fish sauce, sugar, rice vinegar and juice from two limes. Whisk until the sugar has dissolved.
Add in the cilantro, chilies, garlic and ginger and whisk again. Add more rice vinegar if the sauce needs to thin out a bit more. Set this aside, it gets better as the ingredients meld together.
Put a pan on medium heat and add the oil. When the oil is ready, fry the eggs one at a time, basting the oil over the egg white to make the edges crispy.
Remove the eggs from the pan and immediately dip them in the nước chấm. Serve warm :)