Smoky pulled aubergine & black bean tacos

Ingredients

• 2 aubergines -
• 2 tbsp olive oil -
• 1 bay leaf -
• ½ tsp cumin seeds -
• 1 red onion , diced -
• 2 garlic cloves , crushed -
• 1 tbsp tomato purée -
• 400g fresh tomatoes , chopped -
• pinch dried oregano or thyme -
• ½ tsp chilli powder -
• pinch chilli flakes -
• 2 tsp red wine vinegar -
• 2 x 400g cans black beans , 1 drained and rinsed -
• ½ lime , juiced, plus wedges to serve -
• 8 small tortillas , warmed -
• small bunch coriander , leaves picked -
• 50g feta cheese , crumbled -
• ½ iceberg lettuce , shredded -
• pink pickled onions , to serve (see tip, below) -