Many vegetables, like zucchini, cucumber, Summer squash, and eggplant, have a high water content, so to avoid dishes from turning into a diluted, soggy mess, treat the vegetables by salting and draining them first.
The key is to slice or grate the vegetable, sprinkle the cut surfaces with a liberal amount of kosher salt (but don't go overboard!), then wait patiently for 15 minutes for the salt to draw out the water via osmosis. Then, depending on the amount of water brought forth, either pat it dry with a towel or drain away the liquid using a colander.
This process, known as disgorging vegetables, works well for any dish where an excess of liquid would be an issue, such as cucumber salad, eggplant parmesan, a veggie-packed quiche, or any other pastry dish that could turn soggy if vegetables are too moist after cooking. It also helps reduce the bitterness that's sometimes present in older eggplants.