Cut the eggplants into pieces and layer in a colander, sprinkling each layer with salt. This helps draw out any bitter juices. It also stops the flesh from soaking up too much oil if you are frying them. Always cut eggplant with a stainless steel knife to stop them discolouring.
Leave for about 20 minutes to let the eggplants degorge their bitter juices, then rinse thoroughly under cold running water. You can weigh the eggplant down with a plate to speed up the removal of liquid.
Squeeze each piece of eggplant dry, making sure you have got rid of most of the water, then pat dry with paper towels.