Brush eggplant slices with half the oil. Place in a large nonstick pan over medium–high heat. Cook 2 to 3 minutes each side until golden.
Place spinach on a serving platter and top with eggplant, chickpeas, feta, onion and mint.
Combine remaining oil and lemon juice. Pour over salad. Serve at room temperature.
Eggplants with the best flavour are of medium size with thin skins. Larger ones are more likely to be full of seeds and taste bitter. Bitter eggplants may be sprinkled with salt to draw out the flavour. Wash and pat dry before using.