Serves 6

200g Greek yoghurt and 200ml full-fat milk or 400ml of buttermilk (replacing both yoghurt and milk)
2 large stale Turkish flatbread or naan (250g in total)
3 large tomatoes (380g in total), cut into 1.5cm dice
100g radishes, thinly sliced
3 Lebanese or mini cucumbers (250g in total), peeled and chopped into 1.5cm dice
2 spring onions, thinly sliced
15g mint
25g flat-leaf parsley, roughly chopped
1 Tbs dried mint
2 garlic cloves, crushed
3 Tbs lemon juice
60ml olive oil, plus extra to drizzle
2 Tbs cider or white wine vinegar
3/4 tsp coarsely ground black pepper
1 1/2 tsp salt
1 Tbs sumac or more, according to taste, to garnish

1 You could skip the fermentation stage and use buttermilk instead of the combination of milk and yoghurt.

2 If using yoghurt and milk, start at least three hours and up to a day in advance by placing both in a bowl. Whisk well and leave in a cool place or in the fridge until bubbles form on the surface. What you get is a kind of homemade buttermilk, but less sour.

3 Tear the bread into bite-sized pieces and place in a large mixing bowl. Add your fermented yoghurt mixture or commercial buttermilk, followed by the rest of the ingredients, mix well and leave for 10 minutes for all the flavours to combine.

4 Spoon the fattoush into serving bowls, drizzle with some olive oil and garnish generously with sumac.

Jerusalem by Yotam Ottolenghi and Sami Tamimi, is published by Ebury Press, distributed by Random House. RRP $64.99.