Slow cooked lamb shank

Prep:10 mins Cook:5 hrs - 9 Ingredients 4 lamb shanks 2 tbsp olive oil 1 onion, finely chopped 2 tbsp tomato purée 250ml light red wine (such as pinot noir) 2 tbsp plain flour 500ml stock, vegetable, chicken or lamb 2 carrots, chopped 2 garlic cloves, peeled 2 bay leaves 2 thyme spri