Where does “ไข่ดาว” come from?

ไข่ดาว (Thai) comes from Thai ไข่, from Proto-Tai qraj — egg.

ไข่ดาว (Thai): fried egg

Definitions

Step	Language	Word	Meaning
1	Thai	ไข่	egg; roe; spawn; ovoid or round object: ball,...
2	Proto-Tai	qraj	egg

ไข่ดาว — Etymology, Origin & Word History | Etymology Explorer