Meanwhile, cut the potatoes into slices about 5mm thick and simmer in plenty of salted water until just cooked, then carefully drain in a colander.
Brush the aubergine slices with oil – they absorb oil like kitchen paper does, so don’t smother them – then either grill or fry until golden on both sides. They don’t need to be fully cooked – a little underdone is better than fully cooked.
Make the cheese sauce: heat the butter and extra-virgin olive oil together until the butter sizzles, then add the flour and cook for 20 seconds, stirring constantly. Take off the heat and whisk in the warm milk, then return to the stove and bring to a simmer.
Assemble the moussaka by laying half the potatoes on the base of a 3-litre gratin dish, then spread on half of the tomato sauce, followed by half the aubergines and one-third of the cheese sauce. Repeat these layers, finishing with a layer of the cheese sauce. Drizzle with a little extra-virgin olive oil and
Allow to settle and cool for about 5 minutes before serving, garnished with some green leaves if you like.
© 2007 Peter Gordon. All rights reserved.