Sambal udang petai

Ingredients

• 3 red onions, roughly chopped
• 4 garlic cloves, roughly chopped
• 5 cm (2 in) piece ginger, roughly chopped
• 20 g (¾ oz) toasted belacan (shrimp paste; see page 192)
• 150 ml (5 fl oz) vegetable oil
• 1 kg (2 lb 3 oz) banana prawns (shrimp), peeled and deveined, tails intact
• 2 lemongrass stalks, white part only
• 80 g (⅓ cup) basic chilli paste (see page 171)
• 1 kaffir lime leaf, torn once
• 2 tablespoons sugar, plus extra if needed
• 250 g (9 oz) peeled petai (stink beans), halved
• 80 ml (⅓ cup) coconut milk
• 1 teaspoon tamarind paste
• Salt
• Steamed rice, to serve