Authentically Indian version
For the really pukka version of masala omelette, nothing beats the vendors that hang around the front of Ahmedabad station in Gujarat. Most Indian railway stations have blokes selling omelettes of varying styles and quality (usually good, occasionally stellar), often with a distinctive local twist.
The setup is generally one guy wandering around with a portable kerosene stove, a small frying pan, a tin mug to mix everything in, a pot with his particular take on the masala mix and invariably a bag of chopped onion. Order, and he'll squat on the pavement, fire up the stove and knock a two egg one out in 3 or 4 minutes, with two slices of variable quality white bread providing the means of delivery. The Ahmedabad masala is predictably thermonuclear, but the local twist is to put the bread in the upper side of the partially set egg and cook it as half omelette, half eggy bread, with the extra egg at the edges neatly folded into the middle, the bread folded over into a sandwich and both non-egg sides of the bread given a final toasting in the pan. Along with a chai (railway station chai usually excels) its perfect instant gratification for about 20p, quality helped along by Gujarat's generally top-notch eggs.
Sadly it'll only be hangover food if you've come from a big night out in another state or from the island of Diu, because the rest of Gujarat is dry, supposedly out of respect for Gandhi. And if you're heading further into Gujarat, make the most of the Ahmedabad omelettes, because a fair chunk of the middle of the state is seriously vegan and doesn't even do eggs due to the edicts of a revered local 'saint'.