Although the plump, pear-shaped variety, with its near-black shiny-skinned exterior, is probably the most familiar in Britain, aubergines come in a wide variety of shapes, colours and sizes. Aubergines can be bought all year round but they are at their best, not to mention cheapest, from July to September.Aubergines is delicious on the barbecue or cooked slowly in a vegetable curry or ratatouille.