Moroccan Lamb Shanks with Polenta and White Beans

Ingredients

• 1 1/2 cup (300g) dried haricot beans
• 12 french-trimmed lamb shanks (3kg)
• 1/4 cup (35g) plain flour
• 1 tablespoon olive oil
• 2 red onions, chopped finely
• 2 cloves garlic, crushed
• 2 teaspoons ground cumin
• 1/2 teaspoon ground cardamom
• 1/2 teaspoon ground ginger
• 2 teaspoons finely grated lemon rind
• 1/3 cup (80ml) lemon juice
• 2 x 400g cans crushed tomatoes
• 2 1/2 cup (625ml) beef stock
• 1/4 cup (70g) tomato paste
• 3 cups (750ml) water
• 3 cups (750ml) milk
• 2 cups (340g) polenta
• 2 teaspoons finely grated lemon rind, extra
• 1/4 cup finely chopped fresh flat-leaf parsley
• 1/4 cup finely chopped fresh coriander