Irish stew

Name: Irish stew
Prep time: 30 min
Cook time: 2 h
Total time: 2 h 30 min
Cuisine: British
Ingredients: 1 tbsp sunflower oil; 200g smoked streaky bacon preferably in one piece, skinned and cut into chunks; 900g stewing lamb cut into large chunks; 5 medium onions sliced; 5 carrots sliced into chunks; 3 bay leaves; small bunch thyme; 100g pearl barley; 850ml lamb stock; 6 medium potatoes cut into chunks; small knob of butter; 3 spring onions finely sliced