Ham and Cheese Crepes
You'll find ham and cheese crepes being sold by street vendors all over Paris, as well as in cafes and bistros. But it's a classic combination that's popular all over the world, and they're so very easy to make. Optional: garnish with chopped parsley.
The amount of batter that you add to the pan will depend on the size of the pan. An electric crepe maker will typically yield crepes that are about 10-11 inches, but crepe pans or a medium-size skillet usually are about 8-9 inches where you'd use 1/4 cup batter. Electric crepe makers should yield about 8 crepes, and a crepe pan or medium-size skillet should give you about 10-12.
Crepes may be prepared in advance and refrigerated in a sealed plastic bag, so then all you need to do is fill them for a quick meal. Just remove the crepes from the refrigerator in advance or keep them in a low-temperature oven very briefly to take the chill off.
Swiss cheese will not be quite as flavorful, but it can be used as a substitute for Gruyere, if necessary.