Lamb shanks in chilli sauce

Ingredients

• 3 ancho chillies
• 1 cup (250ml) boiling water
• 1 tablespoon olive oil
• 8 (2kg) french-trimmed lamb shanks
• 1 medium_piece (150g) brown onion, chopped finely
• 3 cloves garlic, crushed
• 1 teaspoon ground cumin
• 1/2 teaspoon ground coriander
• 2 sprigs fresh thyme
• 1 litre (4 cups) beef stock
• 2 cups (500ml) water, extra
• 2 dried bay leaves
• 1/3 cup fresh coriander leaves (cilantro), loosely packed
• lime wedges, to serve