Just as with scrambled eggs, the method by which the eggs are heated and stirred is the primary factor that determines what kind of omelette you end up with. This is my basic technique for diner-style omelettes with large, tender, browned curds and plenty of space for fillings.
This recipe is excerpted from J. KENJI LÓPEZ-ALT's book, The Food Lab: Better Home Cooking Through Science.
The Food Lab: Better Home Cooking Through Science$29.97 on Amazon
Whisking the eggs with salt and letting them rest breaks down their protein structure, allowing the omelette to retain more moisture and stay tenderer as it cooks.
Combining the hot ham with the cheese gives it a head start on melting.
Finishing the omelette off-heat keeps it tender and moist.