Cut eggplants (aubergines) lengthways into long thin slices. Heat a ridged grill pan or sturdy frying pan over medium-high heat. Brush eggplant slices with olive oil (you will probably need to do this in batches, so just brush as many as will fit in the pan without overlapping). Cook on both sides until a good golden brown. Transfer to a plate as they are done and season with salt. Cook remaining eggplant.
Alternatively, cook eggplant on a barbecue grill. Brush with a little oil as described and cook on a barbecue grill rack heated to medium. Cook quickly until tender and golden and lightly charred around the edges; you’ll need to move the slices around often as they cook to prevent scorching. Transfer eggplant slices to a plate as they are done and season with sea salt.
Cooked eggplants will keep well in a container for the fridge and can be used in many dishes.
More eggplant tips