Making a pocket-type french omelette without the curd sticking to the pan?
Start with examining your pan closely.
I suspect Pepin's has a good base with even heat distribution (no heat spots) and a good working non stick surface.
Also consider using a wooden spoon/spatula or non stick compliant tool, as you might not be moving the curds quickly enough.

Without pictures or detail, your pan temperature and amount of butter can't be advised.  BTW, it is known as a (French) "Classic Omelette"