Eggplant is high in water content. In fact, the best way to choose an eggplant at the store is to hold it up to your ear like a Cong and tap it to hear the deep thunk it should make when ripe. However, with the high water content also comes some bitter side effects. Many recipes call for salting each side of the eggplant prior to use. I follow this suggestion depending on what I am making...and how much time I have to cook. I tend not to salt when I make Naked Eggplant Parm but I do when roasting and/or frying like when I make the Neo-Traditional Eggplant Parm.
1. Slice Eggplant in rounds or planks
2. Place on sheet pan with parchment (did I mention I hate to clean?)
3. Salt one side and let sit for 10-30 minutes until small beeds of H2O begin to show
4. Pat dry with paper towel
5. Flip and follow same process on opposite side
6. Cook like a rock star!
If you are planning on frying the eggplant, it could also be helpful to press the eggplant between two sheet trays with something heavish item to press the eggplant. This will maximize the water extraction.