Heat 2 tbs evoo in a dutch oven over medium heat.
Add lamb and sear each side for 1-2 minutes until browned. Remove from pan.
Add onion, carrot and celery and cook for 3-5 mins until soft. Add a dash more olive oil if it's sticking.
Add garlic, and fennel and cook a further 3 minutes.
Stir through harissa paste.
Add tomatoes and chicken stock. Bring to a simmer.
Once simmering, add in the pearl barley, and lemon zest.
Return the lamb shank meat back to the dutch oven.
Simmer for 1 hour - 1 30 minutes, or until soup is thick. Lamb should be falling off the bone, or easily shredded with a fork.
To serve, stir through the lemon juice.
Spoon into bowl, then top with greek yogurt (optional), mint or parsley, extra lemon zest and pomegranate.