Aubergine with Buttermilk Sauce

Aubergine with buttermilk sauce

A perfect starter for a light supper. Yogurt sauce, as you may have noticed by now, is a regular presence in my recipes - that's because it has the ability to round up so many flavours and textures like no other component does. Here, I replace some of the yogurt with buttermilk, which adds an acidity that works wonders with the slightly greasy nature of the aubergine and the sweet pomegranate seeds. Za'atar is a Middle Eastern spice blend of sumac, sesame seeds and herbs. Serves four as a starter.

2 large and long aubergines

75ml olive oil

Coarse sea salt and freshly ground black pepper

1 pomegranate

1 tsp za'atar

A few sprigs fresh lemon thyme

For the sauce

140ml buttermilk

100g Greek yogurt

1½ tbsp olive oil, plus a drizzle to finish off

1 small garlic clove, crushed

Pinch salt

Preheat the oven to 200C/400F/gas mark 6. Wash the aubergines and cut them in two lengthways through the green stalk (it looks better like this, even though you don't eat the stalk). Make three or four deep parallel incisions in the cut side of the aubergine, taking care not to cut as far as the skin. Then, at a 45-degree angle to these cuts, make four more, to create a diamond pattern.

Put the aubergines, cut side up, on an oven tray lined with baking parchment and brush with the oil. Keep on brushing until all the oil has soaked into the flesh. Sprinkle with salt and pepper, and roast for 35-40 minutes, at which point the flesh should be soft, flavoursome and well browned. Remove and leave to cool.

While the aubergines are in the oven, cut the pomegranate in two horizontally. Hold one half over a bowl, the cut side facing your palm, and with the back of a wooden spoon gently knock on the skin. Continue beating with increasing power until the seeds start falling into the bowl. Once all are out, sift through the seeds to remove any white skin bits. For the sauce, simply whisk together all the ingredients, taste for seasoning and keep cold until needed.

To serve, put an aubergine half on a plate, flesh side up. Spoon over lots of sauce without covering the stalk, sprinkle on lots of pomegranate seeds and some za'atar, garnish with lemon thyme and finish with a drizzle of oil.

· Yotam Ottolenghi is chef/patron of Ottolenghi in London.