Patlıcanlı rulo börek (Turkish aubergine and pepper filo rolls) - delicious. magazine

Ingredients

• 7 sheets (270g) filo pastry, defrosted if frozen
• 1 tbsp sesame seeds
• 1 tsp nigella seeds
• For the filling
• 2 large or 3 medium aubergines, cut into 1cm cubes
• 7 tbsp olive oil
• 1 onion, finely chopped
• 1 red pepper, finely chopped
• 1 green pepper, finely chopped
• 2 tbsp tomato purée, ideally double concentrated
• 1 medium free-range egg, separated
• 25ml whole milk
• 25ml sparkling water