I also pickle them; for those rainy days of winter when I want to make ratatouille and there are no eggplants around.
When the slices appear translucent, about five-seven minutes in a soft boil, I ladle them out and drain them.
I pack them tightly (in a clean and recently sterilized jar) covering every layer with good olive oil, a thin layer at a time, with chopped parsley and garlic between each layer.
Refrigerate for a minimum of two weeks before using.
Some of the way I use pickled eggplant:
1. sauce for pasta or rice
2. a condiment for sandwiches
3. an addition to scrambled eggs
4. garnish for meats and fowl
5. on toast points for an appetizer
6. as a pizza topping
7. a welcome addition to a grilled cheese sandwich